1
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Peng S, Liu D, Ying Z, An K, Liu C, Feng J, Bai H, Lo KH, Pan H. Industrial-Si-based photoanode for highly efficient and stable water splitting. J Colloid Interface Sci 2024; 671:434-440. [PMID: 38815378 DOI: 10.1016/j.jcis.2024.05.185] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2024] [Revised: 05/21/2024] [Accepted: 05/23/2024] [Indexed: 06/01/2024]
Abstract
Photoelectrochemical (PEC) water splitting is an effective and sustainable method for solar energy harvesting. However, the technology is still far away from practical application because of the high cost and low efficiency. Here, we report a low-cost, stable and high-performing industrial-Si-based photoanode (n-Indus-Si/Co-2mA-xs) that is fabricated by simple electrodeposition. Systematic characterizations such as scanning electron microscopy, X-ray photoelectron spectroscopy have been employed to characterize and understand the working mechanisms of this photoanode. The uniform and adherent dispersion of co-catalyst particles result in high built-in electric field, reduced charge transfer resistance, and abundant active sites. The core-shell structure of co-catalyst particles is formed after the activation process. The reconstructed morphology and modified chemical states of the surface co-catalyst particles improve the separation and transfer of charges, and the reaction kinetics for water oxidation greatly. Our work demonstrates that large-scale PEC water splitting can be achieved by engineering the industrial-Si-based photoelectrode, which shall guide the development of solar energy conversion in the industry.
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Affiliation(s)
- Shuyang Peng
- Department of Electromechanical Engineering, Faculty of Science and Technology, University of Macau, Macao SAR, China
| | - Di Liu
- Institute of Applied Physics and Materials Engineering, University of Macau, Macao SAR, China
| | - Zhiqin Ying
- Ningbo Institute of Materials Technology and Engineering, Chinese Academy of Sciences (CAS), Ningbo City 315201, PR China
| | - Keyu An
- Institute of Applied Physics and Materials Engineering, University of Macau, Macao SAR, China
| | - Chunfa Liu
- Institute of Applied Physics and Materials Engineering, University of Macau, Macao SAR, China
| | - Jinxian Feng
- Institute of Applied Physics and Materials Engineering, University of Macau, Macao SAR, China
| | - Haoyun Bai
- Institute of Applied Physics and Materials Engineering, University of Macau, Macao SAR, China
| | - Kin Ho Lo
- Department of Electromechanical Engineering, Faculty of Science and Technology, University of Macau, Macao SAR, China.
| | - Hui Pan
- Institute of Applied Physics and Materials Engineering, University of Macau, Macao SAR, China; Department of Physics and Chemistry, Faculty of Science and Technology, University of Macau, Macao SAR, China.
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2
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Mancini K, Khatib Y, Shahine L, O’Neil GD. Photoelectrochemistry of Redox-Active Self-Assembled Monolayers Formed on n-Si/Au Nanoparticle Photoelectrodes. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2024; 40:17536-17546. [PMID: 39110768 PMCID: PMC11340028 DOI: 10.1021/acs.langmuir.4c01751] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/10/2024] [Revised: 07/23/2024] [Accepted: 07/24/2024] [Indexed: 08/21/2024]
Abstract
Controlling the chemistry of the electrode-solution interface is critically important for applications in sensing, energy storage, corrosion prevention, molecular electronics, and surface patterning. While numerous methods of chemically modifying electrodes exist, self-assembled monolayers (SAMs) containing redox-active moieties are particularly important because they are easy to prepare, have well-defined interfaces, and can exhibit textbook photoelectrochemistry. Here, we investigate the photoelectrochemistry of redox-active SAMs on semiconductor/metal interfaces, where the SAM is attached to the metal site instead of the semiconductor. n-Si/Au photoelectrodes were fabricated using a benchtop electrodeposition procedure and subsequently modified by immersion in aqueous solutions of (ferrocenyl)hexanethiol and mercaptohexanol. We explored the relevant preparation conditions, finding that after optimization, we were able to obtain canonical cyclic voltammetry for a surface-bound redox molecule that could be turned on and off using light. We then characterized the optimized electrodes under varying illumination intensities, finding that the heterogeneous electron transfer kinetics improved under higher illumination intensities. These results lay the foundation for future studies of semiconductor/metal/molecule interfaces relevant to sensing and electrocatalysis.
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Affiliation(s)
- Kayla
M. Mancini
- Department
of Chemistry and Biochemistry, Montclair
State University, Montclair, New Jersey 07043, United States
| | - Yousef Khatib
- Department
of Chemistry and Biochemistry, Montclair
State University, Montclair, New Jersey 07043, United States
| | - Lauren Shahine
- Department
of Chemistry and Biochemistry, Montclair
State University, Montclair, New Jersey 07043, United States
| | - Glen D. O’Neil
- Department
of Chemistry and Biochemistry, Montclair
State University, Montclair, New Jersey 07043, United States
- Sokol
Institute for Pharmaceutical Life Sciences, Montclair State University, Montclair, New Jersey 07043, United States
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3
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Zhang H, Li S, Xu J, Sun X, Xia J, She G, Yu J, Ru C, Luo J, Meng X, Mu L, Shi W. Dissolution-Induced Surface Reconstruction of Ni 0.95Pt 0.05Si/p-Si Photocathode for Efficient Photoelectrochemical H 2 Production. SMALL (WEINHEIM AN DER BERGSTRASSE, GERMANY) 2024; 20:e2311738. [PMID: 38477695 DOI: 10.1002/smll.202311738] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/13/2024] [Revised: 03/05/2024] [Indexed: 03/14/2024]
Abstract
Metal silicide/Si photoelectrodes have demonstrated significant potential for application in photoelectrochemical (PEC) water splitting to produce H2. To achieve an efficient and economical hydrogen evolution reaction (HER), a paramount consideration lies in attaining exceptional catalytic activity on the metal silicide surface with minimal use of noble metals. Here, this study presents the design and construction of a novel Ni0.95Pt0.05Si/p-Si photocathode. Dopant segregation is used to achieve a Schottky barrier height as high as 1.0 eV and a high photovoltage of 420 mV. To achieve superior electrocatalytic activity for HER, a dissolution-induced surface reconstruction (SR) strategy is proposed to in situ convert surface Ni0.95Pt0.05Si to highly active Pt2Si. The resulting SR Ni0.95Pt0.05Si/p-Si photocathode exhibits excellent HER performance with an onset potential of 0.45 V (vs RHE) and a high maximum photocurrent density of 40.5 mA cm-2 and a remarkable applied bias photon-to-current efficiency (ABPE) of 5.3% under simulated AM 1.5 (100 mW cm-2) illumination. The anti-corrosion silicide layer effectively protects Si, ensuring excellent stability of the SR Ni0.95Pt0.05Si/p-Si photoelectrode. This study highlights the potential for achieving efficient PEC HER using bimetallic silicide/Si photocathodes with reduced Pt consumption, offering an auspicious perspective for the cost-effective conversion of solar energy to chemical energy.
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Affiliation(s)
- Haoyue Zhang
- Key Laboratory of Photochemical Conversion and Optoelectronic Materials, Technical Institute of Physics and Chemistry, Chinese Academy of Sciences, Beijing, 100190, China
- University of Chinese Academy of Sciences, Chinese Academy of Sciences, Beijing, 100049, China
| | - Shengyang Li
- Key Laboratory of Photochemical Conversion and Optoelectronic Materials, Technical Institute of Physics and Chemistry, Chinese Academy of Sciences, Beijing, 100190, China
- Engineered Nanosystems Group, School of Science, Aalto University, Espoo, 02150, Finland
| | - Jing Xu
- Key Laboratory of Microelectronic Devices & Integrated Technology, Institute of Microelectronics, Chinese Academy of Sciences, Beijing, 10009, China
| | - Xianglie Sun
- University of Chinese Academy of Sciences, Chinese Academy of Sciences, Beijing, 100049, China
- Key Laboratory of Microelectronic Devices & Integrated Technology, Institute of Microelectronics, Chinese Academy of Sciences, Beijing, 10009, China
| | - Jing Xia
- Key Laboratory of Photochemical Conversion and Optoelectronic Materials, Technical Institute of Physics and Chemistry, Chinese Academy of Sciences, Beijing, 100190, China
| | - Guangwei She
- Key Laboratory of Photochemical Conversion and Optoelectronic Materials, Technical Institute of Physics and Chemistry, Chinese Academy of Sciences, Beijing, 100190, China
| | - Jiacheng Yu
- Key Laboratory of Photochemical Conversion and Optoelectronic Materials, Technical Institute of Physics and Chemistry, Chinese Academy of Sciences, Beijing, 100190, China
- University of Chinese Academy of Sciences, Chinese Academy of Sciences, Beijing, 100049, China
| | - Changzhou Ru
- Key Laboratory of Photochemical Conversion and Optoelectronic Materials, Technical Institute of Physics and Chemistry, Chinese Academy of Sciences, Beijing, 100190, China
- University of Chinese Academy of Sciences, Chinese Academy of Sciences, Beijing, 100049, China
| | - Jun Luo
- University of Chinese Academy of Sciences, Chinese Academy of Sciences, Beijing, 100049, China
- Key Laboratory of Microelectronic Devices & Integrated Technology, Institute of Microelectronics, Chinese Academy of Sciences, Beijing, 10009, China
| | - Xiangmin Meng
- Key Laboratory of Photochemical Conversion and Optoelectronic Materials, Technical Institute of Physics and Chemistry, Chinese Academy of Sciences, Beijing, 100190, China
- University of Chinese Academy of Sciences, Chinese Academy of Sciences, Beijing, 100049, China
| | - Lixuan Mu
- Key Laboratory of Photochemical Conversion and Optoelectronic Materials, Technical Institute of Physics and Chemistry, Chinese Academy of Sciences, Beijing, 100190, China
| | - Wensheng Shi
- Key Laboratory of Photochemical Conversion and Optoelectronic Materials, Technical Institute of Physics and Chemistry, Chinese Academy of Sciences, Beijing, 100190, China
- University of Chinese Academy of Sciences, Chinese Academy of Sciences, Beijing, 100049, China
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4
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Feng C, Liu Z, Ju H, Mavrič A, Valant M, Fu J, Zhang B, Li Y. Understanding the in-situ transformation of Cu xO interlayers to increase the water splitting efficiency in NiO/n-Si photoanodes. Nat Commun 2024; 15:6436. [PMID: 39085223 PMCID: PMC11291650 DOI: 10.1038/s41467-024-50893-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2023] [Accepted: 07/24/2024] [Indexed: 08/02/2024] Open
Abstract
The buried interface tens of nanometers beneath the solid-liquid junction is crucial for photocarrier extraction, influencing the overall efficiency of photoelectrochemical devices. Precise characterization of the interfacial properties is essential for device optimization but remains challenging. Here, we directly probe the in situ transformation of a CuxO interlayer at the NiO/n-Si interface by hard X-ray photoelectron spectroscopy. It is found that Cu(I) in the CuxO interlayer gradually transforms to Cu(II) with air exposure, forming an energetically more favorable interface and improving photoanode's efficiency. Based on this finding, a reactive e-beam evaporation process is developed for the direct deposition of a CuO interlayer, achieving a half-cell solar-to-hydrogen efficiency of 4.56% for the optimized NiO/CuO/n-Si heterojunction photoanode. Our results highlight the importance of precision characterization of interfacial properties with advanced hard X-ray photoelectron spectroscopy in guiding the design of efficient solar water-splitting devices.
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Affiliation(s)
- Chao Feng
- Institute of Fundamental and Frontier Sciences, University of Electronic Science and Technology of China, Chengdu, China
- Key Laboratory of Quantum Physics and Photonic Quantum Information, Ministry of Education, University of Electronic Science and Technology of China, Chengdu, China
| | - Zhi Liu
- Institute of Fundamental and Frontier Sciences, University of Electronic Science and Technology of China, Chengdu, China
| | - Huanxin Ju
- PHI China Analytical Laboratory, Core Tech Integrated Limited, Nanjing, China
| | - Andraž Mavrič
- Materials Research Laboratory, University of Nova Gorica, Nova Gorica, Slovenia
| | - Matjaz Valant
- Materials Research Laboratory, University of Nova Gorica, Nova Gorica, Slovenia
| | - Jie Fu
- Institute of Fundamental and Frontier Sciences, University of Electronic Science and Technology of China, Chengdu, China
| | - Beibei Zhang
- Institute of Fundamental and Frontier Sciences, University of Electronic Science and Technology of China, Chengdu, China
- Key Laboratory of Quantum Physics and Photonic Quantum Information, Ministry of Education, University of Electronic Science and Technology of China, Chengdu, China
| | - Yanbo Li
- Institute of Fundamental and Frontier Sciences, University of Electronic Science and Technology of China, Chengdu, China.
- Key Laboratory of Quantum Physics and Photonic Quantum Information, Ministry of Education, University of Electronic Science and Technology of China, Chengdu, China.
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5
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Oyetade OA, Wang Y, He S, Margavio HRM, Bottum SR, Rooney CL, Wang H, Donley CL, Parsons GN, Cohen-Karni T, Cahoon JF. Covalent Functionalization of Silicon with Plasma-Grown "Fuzzy" Graphene: Robust Aqueous Photoelectrodes for CO 2 Reduction by Molecular Catalysts. ACS APPLIED MATERIALS & INTERFACES 2024; 16:37885-37895. [PMID: 38996184 DOI: 10.1021/acsami.4c04691] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 07/14/2024]
Abstract
Carbon electrodes are ideal for electrochemistry with molecular catalysts, exhibiting facile charge transfer and good stability. Yet for solar-driven catalysis with semiconductor light absorbers, stable semiconductor/carbon interfaces can be difficult to achieve, and carbon's high optical extinction means it can only be used in ultrathin layers. Here, we demonstrate a plasma-enhanced chemical vapor deposition process that achieves well-controlled deposition of out-of-plane "fuzzy" graphene (FG) on thermally oxidized Si substrates. The resulting Si|FG interfaces possess a silicon oxycarbide (SiOC) interfacial layer, implying covalent bonding between Si and the FG film that is consistent with the mechanical robustness observed from the films. The FG layer is uniform and tunable in thickness and optical transparency by deposition time. Using p-type Si|FG substrates, noncovalent immobilization of cobalt phthalocyanine (CoPc) molecular catalysts was employed for the photoelectrochemical reduction of CO2 in aqueous solution. The Si|FG|CoPc photocathodes exhibited good catalytic activity, yielding a current density of ∼1 mA/cm2, Faradaic efficiency for CO of ∼70% (balance H2), and stable photocurrent for at least 30 h at -1.5 V vs Ag/AgCl under 1-sun illumination. The results suggest that plasma-deposited FG is a robust carbon electrode for molecular catalysts and suitable for further development of aqueous-stable Si photocathodes for CO2 reduction.
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Affiliation(s)
- Oluwaseun A Oyetade
- Department of Chemistry, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599-3290, United States
| | - Yingqiao Wang
- Department of Materials Science and Engineering, Carnegie Mellon University, Pittsburgh, Pennsylvania 15213, United States
| | - Shi He
- Department of Chemistry, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599-3290, United States
| | - Hannah R M Margavio
- Department of Chemical and Biomolecular Engineering, North Carolina State University, Raleigh, North Carolina 27695, United States
| | - Samuel R Bottum
- Department of Chemistry, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599-3290, United States
| | - Conor L Rooney
- Department of Chemistry, Yale University, New Haven, Connecticut 06520, United States
- Energy Sciences Institute, Yale University, West Haven, Connecticut 06516, United States
| | - Hailiang Wang
- Department of Chemistry, Yale University, New Haven, Connecticut 06520, United States
- Energy Sciences Institute, Yale University, West Haven, Connecticut 06516, United States
| | - Carrie L Donley
- Chapel Hill Analytical and Nanofabrication Laboratory (CHANL), University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599, United States
| | - Gregory N Parsons
- Department of Chemical and Biomolecular Engineering, North Carolina State University, Raleigh, North Carolina 27695, United States
| | - Tzahi Cohen-Karni
- Department of Materials Science and Engineering, Carnegie Mellon University, Pittsburgh, Pennsylvania 15213, United States
| | - James F Cahoon
- Department of Chemistry, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599-3290, United States
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6
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King AJ, Weber AZ, Bell AT. Understanding Photovoltage Enhancement in Metal-Insulator Semiconductor Photoelectrodes with Metal Nanoparticles. ACS APPLIED MATERIALS & INTERFACES 2024; 16:36380-36391. [PMID: 38968444 DOI: 10.1021/acsami.4c05928] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 07/07/2024]
Abstract
A metal-insulator-semiconductor (MIS) structure holds great potential to promote photoelectrochemical (PEC) reactions, such as water splitting and CO2 reduction, for the storage of solar energy in chemical bonds. The semiconductor absorbs photons, creating electron-hole pairs; the insulator facilitates charge separation; and the metal collects the desired charge and facilitates its use in the electrochemical reaction. Despite these attractive features, MIS photoelectrodes are significantly limited by their photovoltage, a combination of the voltage generated from photon absorption minus the potential drop across the insulator. Herein, we use multiscale continuum modeling of the carrier, electrolyte, and interfacial transport to identify strategies for mitigating the deleterious potential drop across the insulator and enabling high MIS photovoltages. To this end, we model Ni/SiO2/n-Si photoanodes that employ a planar Ni film or Ni nanoparticles (np-MIS) and validate both models using experimental polarization curves and photovoltage measurements from the literature. The simulations reveal that the insulator potential drop is lower and hence achieves higher photovoltages for np-MIS structures than MIS structures because the electrolyte screens charge trapped at defect states between the semiconductor and the insulator. This electrolyte charge screening phenomenon can be further leveraged by using low loadings or small nanoparticles, which not only minimize the interfacial potential drop but also improve the photocurrent by enabling more light absorption. These insights contribute to the optimization of the np-MIS structures for sustainable energy conversion.
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Affiliation(s)
- Alex J King
- Department of Chemical and Biomolecular Engineering, University of California Berkeley, Berkeley, California 94720, United States
- Liquid Sunlight Alliance, Lawrence Berkeley National Laboratory, Berkeley, California 94720, United States
| | - Adam Z Weber
- Liquid Sunlight Alliance, Lawrence Berkeley National Laboratory, Berkeley, California 94720, United States
| | - Alexis T Bell
- Department of Chemical and Biomolecular Engineering, University of California Berkeley, Berkeley, California 94720, United States
- Liquid Sunlight Alliance, Lawrence Berkeley National Laboratory, Berkeley, California 94720, United States
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7
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Hussain A, Mancini K, Khatib Y, O'Neil GD. Characterizing and understanding the photovoltage in n-Si/Au light-addressable electrochemical sensors. Analyst 2024; 149:3716-3720. [PMID: 38896117 DOI: 10.1039/d4an00768a] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/21/2024]
Abstract
Here, we characterize the photovoltage of n-Si/Au light-addressable electrodes (LAEs) over a range of solution potentials from ca. -1 to +1 V. We find that the n-Si/Au photoelectrodes show photovoltages consistent with a semiconductor/liquid junction in contrast to a buried junction, which opposes our previous understanding of how photovoltage originates in these sensors.
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Affiliation(s)
- Armeen Hussain
- Department of Chemistry and Biochemistry, Montclair State University, Montclair, NJ, 07043 USA.
| | - Kayla Mancini
- Department of Chemistry and Biochemistry, Montclair State University, Montclair, NJ, 07043 USA.
| | - Yousef Khatib
- Department of Chemistry and Biochemistry, Montclair State University, Montclair, NJ, 07043 USA.
| | - Glen D O'Neil
- Department of Chemistry and Biochemistry, Montclair State University, Montclair, NJ, 07043 USA.
- Sokol Institute for Pharmaceutical Life Sciences, Montclair State University, Montclair, NJ, 07043 USA
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8
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Wei S, Xia X, Bi S, Hu S, Wu X, Hsu HY, Zou X, Huang K, Zhang DW, Sun Q, Bard AJ, Yu ET, Ji L. Metal-insulator-semiconductor photoelectrodes for enhanced photoelectrochemical water splitting. Chem Soc Rev 2024; 53:6860-6916. [PMID: 38833171 DOI: 10.1039/d3cs00820g] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/06/2024]
Abstract
Photoelectrochemical (PEC) water splitting provides a scalable and integrated platform to harness renewable solar energy for green hydrogen production. The practical implementation of PEC systems hinges on addressing three critical challenges: enhancing energy conversion efficiency, ensuring long-term stability, and achieving economic viability. Metal-insulator-semiconductor (MIS) heterojunction photoelectrodes have gained significant attention over the last decade for their ability to efficiently segregate photogenerated carriers and mitigate corrosion-induced semiconductor degradation. This review discusses the structural composition and interfacial intricacies of MIS photoelectrodes tailored for PEC water splitting. The application of MIS heterostructures across various semiconductor light-absorbing layers, including traditional photovoltaic-grade semiconductors, metal oxides, and emerging materials, is presented first. Subsequently, this review elucidates the reaction mechanisms and respective merits of vacuum and non-vacuum deposition techniques in the fabrication of the insulator layers. In the context of the metal layers, this review extends beyond the conventional scope, not only by introducing metal-based cocatalysts, but also by exploring the latest advancements in molecular and single-atom catalysts integrated within MIS photoelectrodes. Furthermore, a systematic summary of carrier transfer mechanisms and interface design principles of MIS photoelectrodes is presented, which are pivotal for optimizing energy band alignment and enhancing solar-to-chemical conversion efficiency within the PEC system. Finally, this review explores innovative derivative configurations of MIS photoelectrodes, including back-illuminated MIS photoelectrodes, inverted MIS photoelectrodes, tandem MIS photoelectrodes, and monolithically integrated wireless MIS photoelectrodes. These novel architectures address the limitations of traditional MIS structures by effectively coupling different functional modules, minimizing optical and ohmic losses, and mitigating recombination losses.
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Affiliation(s)
- Shice Wei
- School of Microelectronics & Jiashan Fudan Institute, Fudan University, Shanghai 200433, China.
| | - Xuewen Xia
- School of Materials Science and Engineering, Shanghai University, Shanghai 200444, China.
| | - Shuai Bi
- Department of Chemistry, City University of Hong Kong, 83 Tat Chee Avenue, Kowloon, Hong Kong 999077, China
| | - Shen Hu
- School of Microelectronics & Jiashan Fudan Institute, Fudan University, Shanghai 200433, China.
| | - Xuefeng Wu
- School of Microelectronics & Jiashan Fudan Institute, Fudan University, Shanghai 200433, China.
| | - Hsien-Yi Hsu
- Department of Chemistry, City University of Hong Kong, 83 Tat Chee Avenue, Kowloon, Hong Kong 999077, China
| | - Xingli Zou
- School of Materials Science and Engineering, Shanghai University, Shanghai 200444, China.
| | - Kai Huang
- Department of Physics, Xiamen University, Xiamen 361005, China.
| | - David W Zhang
- School of Microelectronics & Jiashan Fudan Institute, Fudan University, Shanghai 200433, China.
| | - Qinqqing Sun
- School of Microelectronics & Jiashan Fudan Institute, Fudan University, Shanghai 200433, China.
| | - Allen J Bard
- Department of Chemistry, The University of Texas at Austin, Texas 78713, USA
| | - Edward T Yu
- Department of Electrical and Computer Engineering, The University of Texas at Austin, Texas 78758, USA.
| | - Li Ji
- School of Microelectronics & Jiashan Fudan Institute, Fudan University, Shanghai 200433, China.
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9
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Li BH, Zhang KH, Wang XJ, Li YP, Liu X, Han BH, Li FT. Construction synergetic adsorption and activation surface via confined Cu/Cu 2O and Ag nanoparticles on TiO 2 for effective conversion of CO 2 to CH 4. J Colloid Interface Sci 2024; 660:961-973. [PMID: 38281477 DOI: 10.1016/j.jcis.2024.01.159] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2023] [Revised: 01/04/2024] [Accepted: 01/22/2024] [Indexed: 01/30/2024]
Abstract
High-performance photocatalysts for catalytic reduction of CO2 are largely impeded by inefficient charge separation and surface activity. Reasonable design and efficient collaboration of multiple active sites are important for attaining high reactivity and product selectivity. Herein, Cu-Cu2O and Ag nanoparticles are confined as dual sites for assisting CO2 photoreduction to CH4 on TiO2. The introduction of Cu-Cu2O leads to an all-solid-state Z-scheme heterostructure on the TiO2 surface, which achieves efficient electron transfer to Cu2O and adsorption and activation of CO2. The confined nanometallic Ag further enhances the carrier's separation efficiency, promoting the conversion of activated CO2 molecules to •COOH and further conversion to CH4. Particularly, this strategy is highlighted on the TiO2 system for a photocatalytic reduction reaction of CO2 and H2O with a CH4 generation rate of 62.5 μmol∙g-1∙h-1 and an impressive selectivity of 97.49 %. This work provides new insights into developing robust catalysts through the artful design of synergistic catalytic sites for efficient photocatalytic CO2 conversion.
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Affiliation(s)
- Bo-Hui Li
- Hebei Key Laboratory of Photoelectric Control on Surface and Interface, College of Science, Hebei University of Science and Technology, Shijiazhuang 050018, China
| | - Kai-Hua Zhang
- Hebei Key Laboratory of Photoelectric Control on Surface and Interface, College of Science, Hebei University of Science and Technology, Shijiazhuang 050018, China
| | - Xiao-Jing Wang
- Hebei Key Laboratory of Photoelectric Control on Surface and Interface, College of Science, Hebei University of Science and Technology, Shijiazhuang 050018, China.
| | - Yu-Pei Li
- Hebei Key Laboratory of Photoelectric Control on Surface and Interface, College of Science, Hebei University of Science and Technology, Shijiazhuang 050018, China
| | - Xinying Liu
- Institute for the Development of Energy for African Sustainability (IDEAS), University of South Africa (UNISA), Florida 1710, South Africa
| | - Bao-Hang Han
- CAS Key Laboratory of Nanosystem and Hierarchical Fabrication, CAS Center for Excellence in Nanoscience, National Center for Nanoscience and Technology, Beijing 100190, China
| | - Fa-Tang Li
- Hebei Key Laboratory of Photoelectric Control on Surface and Interface, College of Science, Hebei University of Science and Technology, Shijiazhuang 050018, China.
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10
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Diederich J, Velasquez Rojas J, Zare Pour MA, Ruiz Alvarado IA, Paszuk A, Sciotto R, Höhn C, Schwarzburg K, Ostheimer D, Eichberger R, Schmidt WG, Hannappel T, van de Krol R, Friedrich D. Unraveling Electron Dynamics in p-type Indium Phosphide (100): A Time-Resolved Two-Photon Photoemission Study. J Am Chem Soc 2024; 146:8949-8960. [PMID: 38501755 PMCID: PMC10996002 DOI: 10.1021/jacs.3c12487] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2023] [Revised: 03/06/2024] [Accepted: 03/07/2024] [Indexed: 03/20/2024]
Abstract
Renewable ("green") hydrogen production through direct photoelectrochemical (PEC) water splitting is a potential key contributor to the sustainable energy mix of the future. We investigate the potential of indium phosphide (InP) as a reference material among III-V semiconductors for PEC and photovoltaic (PV) applications. The p(2 × 2)/c(4 × 2)-reconstructed phosphorus-terminated p-doped InP(100) (P-rich p-InP) surface is the focus of our investigation. We employ time-resolved two-photon photoemission (tr-2PPE) spectroscopy to study electronic states near the band gap with an emphasis on normally unoccupied conduction band states that are inaccessible through conventional single-photon emission methods. The study shows the complexity of the p-InP electronic band structure and reveals the presence of at least nine distinct states between the valence band edge and vacuum energy, including a valence band state, a surface defect state pinning the Fermi level, six unoccupied surface resonances within the conduction band, as well as a cluster of states about 1.6 eV above the CBM, identified as a bulk-to-surface transition. Furthermore, we determined the decay constants of five of the conduction band states, enabling us to track electron relaxation through the bulk and surface conduction bands. This comprehensive understanding of the electron dynamics in p-InP(100) lays the foundation for further exploration and surface engineering to enhance the properties and applications of p-InP-based III-V-compounds for, e.g., efficient and cost-effective PEC hydrogen production and highly efficient PV cells.
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Affiliation(s)
- Jonathan Diederich
- Institute
for Solar Fuels, Helmholtz-Zentrum Berlin für Materialien und
Energie GmbH, Berlin 14109, Germany
- Institut
für Chemie, Technische Universität
Berlin, Berlin 10623, Germany
| | - Jennifer Velasquez Rojas
- Institute
for Solar Fuels, Helmholtz-Zentrum Berlin für Materialien und
Energie GmbH, Berlin 14109, Germany
- Institut
für Chemie, Technische Universität
Berlin, Berlin 10623, Germany
| | | | | | - Agnieszka Paszuk
- Institut
für Physik, Technische Universität
Ilmenau, Ilmenau 98693, Germany
| | - Rachele Sciotto
- Lehrstuhl
für Theoretische Materialphysik, Universität Paderborn, Paderborn 33095, Germany
| | - Christian Höhn
- Institute
for Solar Fuels, Helmholtz-Zentrum Berlin für Materialien und
Energie GmbH, Berlin 14109, Germany
| | - Klaus Schwarzburg
- Institute
for Solar Fuels, Helmholtz-Zentrum Berlin für Materialien und
Energie GmbH, Berlin 14109, Germany
| | - David Ostheimer
- Institut
für Physik, Technische Universität
Ilmenau, Ilmenau 98693, Germany
| | - Rainer Eichberger
- Institute
for Solar Fuels, Helmholtz-Zentrum Berlin für Materialien und
Energie GmbH, Berlin 14109, Germany
- Institut
für Physik, Technische Universität
Ilmenau, Ilmenau 98693, Germany
| | - Wolf Gero Schmidt
- Lehrstuhl
für Theoretische Materialphysik, Universität Paderborn, Paderborn 33095, Germany
| | - Thomas Hannappel
- Institut
für Physik, Technische Universität
Ilmenau, Ilmenau 98693, Germany
| | - Roel van de Krol
- Institute
for Solar Fuels, Helmholtz-Zentrum Berlin für Materialien und
Energie GmbH, Berlin 14109, Germany
- Institut
für Chemie, Technische Universität
Berlin, Berlin 10623, Germany
| | - Dennis Friedrich
- Institute
for Solar Fuels, Helmholtz-Zentrum Berlin für Materialien und
Energie GmbH, Berlin 14109, Germany
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11
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Liao Z, Li J, Long Y, Sheng H, Wang X, Li X, Guo W, Yin J. Simultaneous Sensing of Velocity and Position of a Moving Light Source Using Metal-Insulator-Semiconductor Structures. ACS APPLIED MATERIALS & INTERFACES 2023. [PMID: 38019552 DOI: 10.1021/acsami.3c12722] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/30/2023]
Abstract
Photodetectors based on semiconductor devices have been widely used to sense light position, intensity, and wavelength. However, monitoring the motion velocity of a light beam generally requires complex integration of device arrays. Here, we report a single device of a simple metal-insulator-semiconductor structure for self-powered sensing not only position but also velocity of a light beam or shadow. A velocity-dependent voltage output between two terminals of the metal is observed. It is attributed to light illumination-induced local surface potential change in semiconductors and the following movement of local charges accumulated in the metal due to capacitive coupling. The amplitude of the velocity-dependent voltage can be facilely modulated by applying a gate voltage. These results shed light on compact devices with multiple sensing functions.
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Affiliation(s)
- Zixuan Liao
- College of Aerospace Engineering, Nanjing University of Aeronautics and Astronautics, Nanjing 210016, P. R. China
| | - Jidong Li
- State Key Laboratory of Mechanics and Control of Mechanical Structures, Key Laboratory for Intelligent Nano Materials and Devices of the Ministry of Education, and Institute for Frontier Science, Nanjing University of Aeronautics and Astronautics, Nanjing 210016, P. R. China
| | - Yuyang Long
- College of Aerospace Engineering, Nanjing University of Aeronautics and Astronautics, Nanjing 210016, P. R. China
| | - Han Sheng
- College of Aerospace Engineering, Nanjing University of Aeronautics and Astronautics, Nanjing 210016, P. R. China
| | - Xiao Wang
- College of Aerospace Engineering, Nanjing University of Aeronautics and Astronautics, Nanjing 210016, P. R. China
| | - Xuemei Li
- State Key Laboratory of Mechanics and Control of Mechanical Structures, Key Laboratory for Intelligent Nano Materials and Devices of the Ministry of Education, and Institute for Frontier Science, Nanjing University of Aeronautics and Astronautics, Nanjing 210016, P. R. China
- College of Material Science and Engineering, Nanjing University of Aeronautics and Astronautics, Nanjing 210016, P. R. China
| | - Wanlin Guo
- College of Aerospace Engineering, Nanjing University of Aeronautics and Astronautics, Nanjing 210016, P. R. China
- State Key Laboratory of Mechanics and Control of Mechanical Structures, Key Laboratory for Intelligent Nano Materials and Devices of the Ministry of Education, and Institute for Frontier Science, Nanjing University of Aeronautics and Astronautics, Nanjing 210016, P. R. China
| | - Jun Yin
- College of Aerospace Engineering, Nanjing University of Aeronautics and Astronautics, Nanjing 210016, P. R. China
- State Key Laboratory of Mechanics and Control of Mechanical Structures, Key Laboratory for Intelligent Nano Materials and Devices of the Ministry of Education, and Institute for Frontier Science, Nanjing University of Aeronautics and Astronautics, Nanjing 210016, P. R. China
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12
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Descamps J, Zhao Y, Le-Pouliquen J, Goudeau B, Garrigue P, Tavernier K, Léger Y, Loget G, Sojic N. Local reactivity of metal-insulator-semiconductor photoanodes imaged by photoinduced electrochemiluminescence microscopy. Chem Commun (Camb) 2023; 59:12262-12265. [PMID: 37753612 DOI: 10.1039/d3cc03702a] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 09/28/2023]
Abstract
Localized photoinduced electrochemiluminescence (PECL) is studied on photoanodes composed of Ir microbands deposited on n-Si/SiOx. We demonstrate that PECL microscopy precisely imaged the hole-driven heterogeneous photoelectrochemical reactivity. The method is promising for elucidating the local activity of photoelectrodes that are employed in solar energy conversion.
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Affiliation(s)
- Julie Descamps
- University of Bordeaux, Bordeaux INP, ISM, UMR CNRS 5255, Pessac 33607, France.
| | - Yiran Zhao
- Univ Rennes, CNRS, ISCR (Institut des Sciences Chimiques de Rennes)-UMR6226, Rennes F-35000, France.
| | - Julie Le-Pouliquen
- Univ Rennes, INSA Rennes, CNRS, Institut FOTON-UMR 6082, F-35000, Rennes, France
| | - Bertrand Goudeau
- University of Bordeaux, Bordeaux INP, ISM, UMR CNRS 5255, Pessac 33607, France.
| | - Patrick Garrigue
- University of Bordeaux, Bordeaux INP, ISM, UMR CNRS 5255, Pessac 33607, France.
| | - Karine Tavernier
- Univ Rennes, INSA Rennes, CNRS, Institut FOTON-UMR 6082, F-35000, Rennes, France
| | - Yoan Léger
- Univ Rennes, INSA Rennes, CNRS, Institut FOTON-UMR 6082, F-35000, Rennes, France
| | - Gabriel Loget
- Univ Rennes, CNRS, ISCR (Institut des Sciences Chimiques de Rennes)-UMR6226, Rennes F-35000, France.
- Institute of Energy and Climate Research, Fundamental Electrochemistry (IEK-9), Forschungszentrum Jülich GmbH, Jülich, 52425, Germany
| | - Neso Sojic
- University of Bordeaux, Bordeaux INP, ISM, UMR CNRS 5255, Pessac 33607, France.
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13
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Ragonese P, Kalinic B, Franco L, Girardi L, Fernández Peréz BM, Carbonera D, Mattei G, Rizzi GA, Maurizio C. Effect of Interfacial SiO x Defects on the Functional Properties of Si-Transition Metal Oxide Photoanodes for Water Splitting. ACS APPLIED MATERIALS & INTERFACES 2023; 15:46933-46940. [PMID: 37782757 PMCID: PMC10571009 DOI: 10.1021/acsami.3c09555] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/03/2023] [Accepted: 09/19/2023] [Indexed: 10/04/2023]
Abstract
The transfer of photogenerated charges through interfaces in heterojunction photoanodes is a key process that controls the efficiency of solar water splitting. Considering Co3O4/SiOx/Si photoanodes prepared by physical vapor deposition as a representative case study, it is shown that defects normally present in the native SiOx layer dramatically affect the onset of the photocurrent. Electron paramagnetic resonance indicates that the signal of defects located in dangling bonds of trivalent Si atoms at the Si/SiOx interface vanishes upon vacuum annealing at 850 °C. Correspondingly, the photovoltage of the photoanode increases to ≈500 mV. Similar results are obtained for NiO/SiOx/Si photoanodes. Photoelectrochemical analysis and impedance spectroscopy (in solution and in the solid state) indicate how the defect annealing modifies the Co3O4/SiOx/Si junction. This work shows that defect annealing at the solid-solid interface in composite photoanodes strongly improves the efficiency of charge transfer through interfaces, which is the basis for effective solar-to-chemical energy conversion.
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Affiliation(s)
- P. Ragonese
- Physics
and Astronomy Department, University of
Padova, Via Marzolo 8, Padova I-35131, Italy
| | - B. Kalinic
- Physics
and Astronomy Department, University of
Padova, Via Marzolo 8, Padova I-35131, Italy
| | - L. Franco
- Department
of Chemical Sciences, University of Padova, Via Marzolo 1, Padova I-35131, Italy
| | - L. Girardi
- Department
of Chemical Sciences, University of Padova, Via Marzolo 1, Padova I-35131, Italy
| | - B. M. Fernández Peréz
- Physics
and Astronomy Department, University of
Padova, Via Marzolo 8, Padova I-35131, Italy
| | - D. Carbonera
- Department
of Chemical Sciences, University of Padova, Via Marzolo 1, Padova I-35131, Italy
| | - G. Mattei
- Physics
and Astronomy Department, University of
Padova, Via Marzolo 8, Padova I-35131, Italy
| | - G.-A. Rizzi
- Department
of Chemical Sciences, University of Padova, Via Marzolo 1, Padova I-35131, Italy
| | - C. Maurizio
- Physics
and Astronomy Department, University of
Padova, Via Marzolo 8, Padova I-35131, Italy
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14
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Kim MJ, Bae JS, Jung MJ, Jeon E, Park Y, Khan H, Kwon SH. Atomic Layer Deposition of Defective Amorphous TiO x Thin Films with Improved Photoelectrochemical Performance. ACS APPLIED MATERIALS & INTERFACES 2023; 15:45732-45744. [PMID: 37734915 DOI: 10.1021/acsami.3c06780] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 09/23/2023]
Abstract
A proper control of defects in TiO2 thin films is challenging work for enhancing the photoelectrochemical (PEC) efficiency in water splitting processes. Additionally, a deep understanding of how defects affect the PEC performance of TiO2 thin films is of great interest for achieving better performance. With these aims, we prepared defective amorphous TiOx thin films at various growth temperatures by atomic layer deposition using tetrakis(dimethylamido)titanium as the Ti precursor. Careful X-ray photoelectron spectroscopy and electron spin resonance spectroscopy analyses revealed that the defect concentration in the TiOx thin films can be controlled by adjusting the growth temperature during the ALD process. We also evaluated the light absorption properties of the deposited TiOx thin films using ultraviolet-visible absorption spectroscopy. And it was found that the TiOx thin film deposited at a growth temperature of 200 °C exhibited the highest defect concentration and the highest photocurrent density of 0.051 mA/cm2 at 1.23 V vs reversible hydrogen electrode (RHE) compared to those of the other films. The light absorption efficiency, photogenerated charge separation efficiency, and charge transfer efficiency of defective amorphous TiOx thin films were carefully studied to understand the correlation between the defect concentration in the prepared TiOx thin film and its PEC activity. This study provides insight into the PEC properties of defective amorphous ALD-TiOx thin films.
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Affiliation(s)
- Min-Ji Kim
- School of Materials Science and Engineering, Pusan National University, Busan 46241, Republic of Korea
| | - Jong-Seong Bae
- Division of Analysis and Research, Korea Basic Science Institute, Busan 46742, Republic of Korea
| | - Myung-Jin Jung
- School of Materials Science and Engineering, Pusan National University, Busan 46241, Republic of Korea
| | - Eunsong Jeon
- Department of Chemical Engineering, Pukyong National University, Busan 48513, Republic of Korea
| | - Yiseul Park
- Department of Chemical Engineering, Pukyong National University, Busan 48513, Republic of Korea
| | - Hasmat Khan
- School of Materials Science and Engineering, Pusan National University, Busan 46241, Republic of Korea
- Institute of Materials Technology, Pusan National University, Busan 46241, Republic of Korea
| | - Se-Hun Kwon
- School of Materials Science and Engineering, Pusan National University, Busan 46241, Republic of Korea
- Institute of Materials Technology, Pusan National University, Busan 46241, Republic of Korea
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15
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Ho HC, Smiljanić M, Jovanović Z, Čekada M, Kovač J, Koster G, Hlinka J, Hodnik N, Spreitzer M. Robust SrTiO 3 Passivation of Silicon Photocathode by Reduced Graphene Oxide for Solar Water Splitting. ACS APPLIED MATERIALS & INTERFACES 2023; 15:44482-44492. [PMID: 37695941 PMCID: PMC10520914 DOI: 10.1021/acsami.3c07747] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/30/2023] [Accepted: 08/30/2023] [Indexed: 09/13/2023]
Abstract
Development of a robust photocathode using low-cost and high-performing materials, e.g., p-Si, to produce clean fuel hydrogen has remained challenging since the semiconductor substrate is easily susceptible to (photo)corrosion under photoelectrochemical (PEC) operational conditions. A protective layer over the substrate to simultaneously provide corrosion resistance and maintain efficient charge transfer across the device is therefore needed. To this end, in the present work, we utilized pulsed laser deposition (PLD) to prepare a high-quality SrTiO3 (STO) layer to passivate the p-Si substrate using a buffer layer of reduced graphene oxide (rGO). Specifically, a very thin (3.9 nm ∼10 unit cells) STO layer epitaxially overgrown on rGO-buffered Si showed the highest onset potential (0.326 V vs RHE) in comparison to the counterparts with thicker and/or nonepitaxial STO. The photovoltage, flat-band potential, and electrochemical impedance spectroscopy measurements revealed that the epitaxial photocathode was more beneficial for charge separation, charge transfer, and targeted redox reaction than the nonepitaxial one. The STO/rGO/Si with a smooth and highly epitaxial STO layer outperforming the directly contacted STO/Si with a textured and polycrystalline STO layer showed the importance of having a well-defined passivation layer. In addition, the numerous pinholes formed in the directly contacted STO/Si led to the rapid degradation of the photocathode during the PEC measurements. The stability tests demonstrated the soundness of the epitaxial STO layer in passivating Si against corrosion. This study provided a facile approach for preparing a robust protection layer over a photoelectrode substrate in realizing an efficient and, at the same time, durable PEC device.
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Affiliation(s)
- Hsin-Chia Ho
- Advanced
Materials Department, Jožef Stefan
Institute, 1000 Ljubljana, Slovenia
| | - Milutin Smiljanić
- Department
of Materials Chemistry, National Institute
of Chemistry, 1000 Ljubljana, Slovenia
| | - Zoran Jovanović
- Advanced
Materials Department, Jožef Stefan
Institute, 1000 Ljubljana, Slovenia
- Laboratory
of Physics, Vinča Institute of Nuclear Sciences—National
Institute of the Republic of Serbia, University
of Belgrade, 11351 Belgrade, Serbia
| | - Miha Čekada
- Department
of Thin Films and Surfaces, Jožef
Stefan Institute, 1000 Ljubljana, Slovenia
| | - Janez Kovač
- Department
of Surface Engineering, Jožef Stefan
Institute, 1000 Ljubljana, Slovenia
| | - Gertjan Koster
- MESA+
Institute for Nanotechnology, University
of Twente, Enschede 7522, NB, The Netherlands
| | - Jiří Hlinka
- Department
of Dielectrics, Institute of Physics of
the Czech Academy of Sciences, 182 00 Prague, Czech
Republic
| | - Nejc Hodnik
- Department
of Materials Chemistry, National Institute
of Chemistry, 1000 Ljubljana, Slovenia
| | - Matjaž Spreitzer
- Advanced
Materials Department, Jožef Stefan
Institute, 1000 Ljubljana, Slovenia
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16
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King AJ, Weber AZ, Bell AT. Theory and Simulation of Metal-Insulator-Semiconductor (MIS) Photoelectrodes. ACS APPLIED MATERIALS & INTERFACES 2023; 15:23024-23039. [PMID: 37154402 DOI: 10.1021/acsami.2c21114] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/10/2023]
Abstract
A metal-insulator-semiconductor (MIS) structure is an attractive photoelectrode-catalyst architecture for promoting photoelectrochemical reactions, such as the formation of H2 by proton reduction. The metal catalyzes the generation of H2 using electrons generated by photon absorption and charge separation in the semiconductor. The insulator layer between the metal and the semiconductor protects the latter element from photo-corrosion and, also, significantly impacts the photovoltage at the metal surface. Understanding how the insulator layer determines the photovoltage and what properties lead to high photovoltages is critical to the development of MIS structures for solar-to-chemical energy conversion. Herein, we present a continuum model for charge-carrier transport from the semiconductor to the metal with an emphasis on mechanisms of charge transport across the insulator. The polarization curves and photovoltages predicted by this model for a Pt/HfO2/p-Si MIS structure at different HfO2 thicknesses agree well with experimentally measured data. The simulations reveal how insulator properties (i.e., thickness and band structure) affect band bending near the semiconductor/insulator interface and how tuning them can lead to operation closer to the maximally attainable photovoltage, the flat-band potential. This phenomenon is understood by considering the change in tunneling resistance with insulator properties. The model shows that the best MIS performance is attained with highly symmetric semiconductor/insulator band offsets (e.g., BeO, MgO, SiO2, HfO2, or ZrO2 deposited on Si) and a low to moderate insulator thickness (e.g., between 0.8 and 1.5 nm). Beyond 1.5 nm, the density of filled interfacial trap sites is high and significantly limits the photovoltage and the solar-to-chemical conversion rate. These conclusions are true for photocathodes and photoanodes. This understanding provides critical insight into the phenomena enhancing and limiting photoelectrode performance and how this phenomenon is influenced by insulator properties. The study gives guidance toward the development of next-generation insulators for MIS structures that achieve high performance.
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Affiliation(s)
- Alex J King
- Department of Chemical and Biomolecular Engineering, University of California Berkeley, Berkeley, California 94720, United States
- Liquid Sunlight Alliance, Lawrence Berkeley National Laboratory, Berkeley, California 94720, United States
| | - Adam Z Weber
- Liquid Sunlight Alliance, Lawrence Berkeley National Laboratory, Berkeley, California 94720, United States
| | - Alexis T Bell
- Department of Chemical and Biomolecular Engineering, University of California Berkeley, Berkeley, California 94720, United States
- Liquid Sunlight Alliance, Lawrence Berkeley National Laboratory, Berkeley, California 94720, United States
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17
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Wang S, Feng S, Liu B, Gong Z, Wang T, Gong J. An integrated n-Si/BiVO 4 photoelectrode with an interfacial bi-layer for unassisted solar water splitting. Chem Sci 2023; 14:2192-2199. [PMID: 36845941 PMCID: PMC9945263 DOI: 10.1039/d2sc06651c] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2022] [Accepted: 01/29/2023] [Indexed: 01/31/2023] Open
Abstract
Integrated n-Si/BiVO4 is one of the most promising candidates for unbiased photoelectrochemical water splitting. However, a direct connection between n-Si and BiVO4 will not attain overall water splitting due to the small band offset as well as the interfacial defects at the n-Si/BiVO4 interface that severely impede carrier separation and transport, limiting the photovoltage generation. This paper describes the design and fabrication of an integrated n-Si/BiVO4 device with enhanced photovoltage extracted from the interfacial bi-layer for unassisted water splitting. An Al2O3/indium tin oxide (ITO) interfacial bi-layer was inserted at the n-Si/BiVO4 interface, which promotes the interfacial carrier transport by enlarging the band offset while healing interfacial defects. When coupled to a separate cathode for hydrogen evolution, spontaneous water splitting could be realized with this n-Si/Al2O3/ITO/BiVO4 tandem anode, with an average solar-to-hydrogen (STH) efficiency of 0.62% for over 1000 hours.
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Affiliation(s)
- Shujie Wang
- School of Chemical Engineering and Technology, Key Laboratory for Green Chemical Technology of Ministry of Education, Tianjin University Tianjin 300072 China
- Collaborative Innovation Center of Chemical Science and Engineering (Tianjin) Tianjin 300072 China
| | - Shijia Feng
- School of Chemical Engineering and Technology, Key Laboratory for Green Chemical Technology of Ministry of Education, Tianjin University Tianjin 300072 China
- Collaborative Innovation Center of Chemical Science and Engineering (Tianjin) Tianjin 300072 China
| | - Bin Liu
- School of Chemical Engineering and Technology, Key Laboratory for Green Chemical Technology of Ministry of Education, Tianjin University Tianjin 300072 China
- Collaborative Innovation Center of Chemical Science and Engineering (Tianjin) Tianjin 300072 China
| | - Zichen Gong
- School of Chemical Engineering and Technology, Key Laboratory for Green Chemical Technology of Ministry of Education, Tianjin University Tianjin 300072 China
- Collaborative Innovation Center of Chemical Science and Engineering (Tianjin) Tianjin 300072 China
| | - Tuo Wang
- School of Chemical Engineering and Technology, Key Laboratory for Green Chemical Technology of Ministry of Education, Tianjin University Tianjin 300072 China
- Collaborative Innovation Center of Chemical Science and Engineering (Tianjin) Tianjin 300072 China
- Haihe Laboratory of Sustainable Chemical Transformations Tianjin 300192 China
- Joint School of National University of Singapore and Tianjin University International Campus of Tianjin University, Binhai New City Fuzhou 350207 China
- National Industry-Education Platform of Energy Storage Tianjin 300350 China
| | - Jinlong Gong
- School of Chemical Engineering and Technology, Key Laboratory for Green Chemical Technology of Ministry of Education, Tianjin University Tianjin 300072 China
- Collaborative Innovation Center of Chemical Science and Engineering (Tianjin) Tianjin 300072 China
- Haihe Laboratory of Sustainable Chemical Transformations Tianjin 300192 China
- National Industry-Education Platform of Energy Storage Tianjin 300350 China
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18
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Upconversion Photoinduced Electrochemiluminescence of Luminol-H2O2 at Si/SiOx/Ni Photoanodes. Electrochim Acta 2023. [DOI: 10.1016/j.electacta.2023.142013] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
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19
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Ma J, Chi H, Wang A, Wang P, Jing H, Yao T, Li C. Identifying and Removing the Interfacial States in Metal-Oxide–Semiconductor Schottky Si Photoanodes for the Highest Fill Factor. J Am Chem Soc 2022; 144:17540-17548. [DOI: 10.1021/jacs.2c06748] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Jiangping Ma
- Key Laboratory of Advanced Catalysis, Gansu Province; State Key Laboratory of Applied Organic Chemistry, College of Chemistry and Chemical Engineering, Lanzhou University, Lanzhou, Gansu 730000, China
- State Key Laboratory of Catalysis, Dalian Institute of Chemical Physics, Dalian National Laboratory for Clean Energy, Chinese Academy of Sciences, Dalian 116023, China
| | - Haibo Chi
- State Key Laboratory of Catalysis, Dalian Institute of Chemical Physics, Dalian National Laboratory for Clean Energy, Chinese Academy of Sciences, Dalian 116023, China
- School of Chemical and Materials Science, University of Science and Technology of China, Hefei, Anhui 230026, China
| | - Aoqi Wang
- State Key Laboratory of Catalysis, Dalian Institute of Chemical Physics, Dalian National Laboratory for Clean Energy, Chinese Academy of Sciences, Dalian 116023, China
- School of Chemical and Materials Science, University of Science and Technology of China, Hefei, Anhui 230026, China
| | - Pengpeng Wang
- State Key Laboratory of Catalysis, Dalian Institute of Chemical Physics, Dalian National Laboratory for Clean Energy, Chinese Academy of Sciences, Dalian 116023, China
| | - Huanwang Jing
- Key Laboratory of Advanced Catalysis, Gansu Province; State Key Laboratory of Applied Organic Chemistry, College of Chemistry and Chemical Engineering, Lanzhou University, Lanzhou, Gansu 730000, China
| | - Tingting Yao
- State Key Laboratory of Catalysis, Dalian Institute of Chemical Physics, Dalian National Laboratory for Clean Energy, Chinese Academy of Sciences, Dalian 116023, China
| | - Can Li
- Key Laboratory of Advanced Catalysis, Gansu Province; State Key Laboratory of Applied Organic Chemistry, College of Chemistry and Chemical Engineering, Lanzhou University, Lanzhou, Gansu 730000, China
- State Key Laboratory of Catalysis, Dalian Institute of Chemical Physics, Dalian National Laboratory for Clean Energy, Chinese Academy of Sciences, Dalian 116023, China
- School of Chemical and Materials Science, University of Science and Technology of China, Hefei, Anhui 230026, China
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20
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Zhao Y, Descamps J, Ababou-Girard S, Bergamini JF, Santinacci L, Léger Y, Sojic N, Loget G. Metal-Insulator-Semiconductor Anodes for Ultrastable and Site-Selective Upconversion Photoinduced Electrochemiluminescence. Angew Chem Int Ed Engl 2022; 61:e202201865. [PMID: 35233901 DOI: 10.1002/anie.202201865] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2022] [Indexed: 12/27/2022]
Abstract
Photoinduced electrochemiluminescence (PECL) allows the electrochemically assisted conversion of low-energy photons into high-energy photons at an electrode surface. This concept is expected to have important implications, however, it is dramatically limited by the stability of the surface, impeding future developments. Here, a series of metal-insulator-semiconductor (MIS) junctions, using photoactive n-type Si (n-Si) as a light absorber covered by a few-nanometer-thick protective SiOx /metal (SiOx /M, with M=Ru, Pt, and Ir) overlayers are investigated for upconversion PECL of the model co-reactant system involving the simultaneous oxidation of tris(bipyridine)ruthenium(II) and tri-n-propylamine. We show that n-Si/SiOx /Pt and n-Si/SiOx /Ir exhibit high photovoltages and record stabilities in operation (35 h for n-Si/SiOx /Ir) for the generation of intense PECL with an anti-Stokes shift of 218 nm. We also demonstrate that these surfaces can be employed for spatially localized PECL. These unprecedented performances are extremely promising for future applications of PECL.
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Affiliation(s)
- Yiran Zhao
- Univ Rennes, CNRS, ISCR (Institut des Sciences Chimiques de Rennes) UMR 6226, 35000, Rennes, France
| | - Julie Descamps
- University of Bordeaux, Bordeaux INP, ISM, UMR CNRS 5255, 33607, Pessac, France
| | - Soraya Ababou-Girard
- Univ Rennes, CNRS, IPR (Institut de Physique de Rennes) UMR 6251, 35000, Rennes, France
| | - Jean-François Bergamini
- Univ Rennes, CNRS, ISCR (Institut des Sciences Chimiques de Rennes) UMR 6226, 35000, Rennes, France
| | | | - Yoan Léger
- Univ Rennes, INSA Rennes, CNRS, Institut FOTON-UMR 6082, 35000, Rennes, France
| | - Neso Sojic
- University of Bordeaux, Bordeaux INP, ISM, UMR CNRS 5255, 33607, Pessac, France
| | - Gabriel Loget
- Univ Rennes, CNRS, ISCR (Institut des Sciences Chimiques de Rennes) UMR 6226, 35000, Rennes, France
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21
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Zhao Y, Descamps J, Ababou‐Girard S, Bergamini J, Santinacci L, Léger Y, Sojic N, Loget G. Metal‐Insulator‐Semiconductor Anodes for Ultrastable and Site‐Selective Upconversion Photoinduced Electrochemiluminescence. Angew Chem Int Ed Engl 2022. [DOI: 10.1002/ange.202201865] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Affiliation(s)
- Yiran Zhao
- Univ Rennes, CNRS, ISCR (Institut des Sciences Chimiques de Rennes) UMR 6226 35000 Rennes France
| | - Julie Descamps
- University of Bordeaux, Bordeaux INP, ISM, UMR CNRS 5255 33607 Pessac France
| | - Soraya Ababou‐Girard
- Univ Rennes, CNRS, IPR (Institut de Physique de Rennes) UMR 6251 35000 Rennes France
| | - Jean‐François Bergamini
- Univ Rennes, CNRS, ISCR (Institut des Sciences Chimiques de Rennes) UMR 6226 35000 Rennes France
| | | | - Yoan Léger
- Univ Rennes, INSA Rennes, CNRS, Institut FOTON-UMR 6082 35000 Rennes France
| | - Neso Sojic
- University of Bordeaux, Bordeaux INP, ISM, UMR CNRS 5255 33607 Pessac France
| | - Gabriel Loget
- Univ Rennes, CNRS, ISCR (Institut des Sciences Chimiques de Rennes) UMR 6226 35000 Rennes France
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22
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Saari J, Ali-Löytty H, Honkanen M, Tukiainen A, Lahtonen K, Valden M. Interface Engineering of TiO 2 Photoelectrode Coatings Grown by Atomic Layer Deposition on Silicon. ACS OMEGA 2021; 6:27501-27509. [PMID: 34693171 PMCID: PMC8529674 DOI: 10.1021/acsomega.1c04478] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 08/17/2021] [Accepted: 09/24/2021] [Indexed: 06/13/2023]
Abstract
Titanium dioxide (TiO2) can protect photoelectrochemical (PEC) devices from corrosion, but the fabrication of high-quality TiO2 coatings providing long-term stability has remained challenging. Here, we compare the influence of Si wafer cleaning and postdeposition annealing temperature on the performance of TiO2/n+-Si photoanodes grown by atomic layer deposition (ALD) using tetrakis(dimethylamido)titanium (TDMAT) and H2O as precursors at a growth temperature of 100 °C. We show that removal of native Si oxide before ALD does not improve the TiO2 coating performance under alkaline PEC water splitting conditions if excessive postdeposition annealing is needed to induce crystallization. The as-deposited TiO2 coatings were amorphous and subject to photocorrosion. However, the TiO2 coatings were found to be stable over a time period of 10 h after heat treatment at 400 °C that induced crystallization of amorphous TiO2 into anatase TiO2. No interfacial Si oxide formed during the ALD growth, but during the heat treatment, the thickness of interfacial Si oxide increased to 1.8 nm for all of the samples. Increasing the ALD growth temperature to 150 °C enabled crystallization at 300 °C, which resulted in reduced growth of interfacial Si oxide followed by a 70 mV improvement in the photocurrent onset potential.
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Affiliation(s)
- Jesse Saari
- Surface
Science Group, Faculty of Engineering and Natural Sciences, Tampere University, P.O. Box 692, FI 33014 Tampere, Finland
| | - Harri Ali-Löytty
- Surface
Science Group, Faculty of Engineering and Natural Sciences, Tampere University, P.O. Box 692, FI 33014 Tampere, Finland
| | - Mari Honkanen
- Tampere
Microscopy Center, Faculty of Engineering and Natural Sciences, Tampere University, P.O.
Box 692, FI 33014 Tampere, Finland
| | - Antti Tukiainen
- Faculty
of Engineering and Natural Sciences, Tampere
University, P.O. Box 692, FI 33014 Tampere, Finland
| | - Kimmo Lahtonen
- Faculty
of Engineering and Natural Sciences, Tampere
University, P.O. Box 692, FI 33014 Tampere, Finland
| | - Mika Valden
- Surface
Science Group, Faculty of Engineering and Natural Sciences, Tampere University, P.O. Box 692, FI 33014 Tampere, Finland
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23
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Li J, Long Y, Hu Z, Niu J, Xu T, Yu M, Li B, Li X, Zhou J, Liu Y, Wang C, Shen L, Guo W, Yin J. Kinetic photovoltage along semiconductor-water interfaces. Nat Commun 2021; 12:4998. [PMID: 34404782 PMCID: PMC8371154 DOI: 10.1038/s41467-021-25318-8] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2021] [Accepted: 08/03/2021] [Indexed: 11/09/2022] Open
Abstract
External photo-stimuli on heterojunctions commonly induce an electric potential gradient across the interface therein, such as photovoltaic effect, giving rise to various present-day technical devices. In contrast, in-plane potential gradient along the interface has been rarely observed. Here we show that scanning a light beam can induce a persistent in-plane photoelectric voltage along, instead of across, silicon-water interfaces. It is attributed to the following movement of a charge packet in the vicinity of the silicon surface, whose formation is driven by the light-induced potential change across the capacitive interface and a high permittivity of water with large polarity. Other polar liquids and hydrogel on silicon also allow the generation of the in-plane photovoltage, which is, however, negligible for nonpolar liquids. Based on the finding, a portable silicon-hydrogel array has been constructed for detecting the shadow path of a moving Cubaris. Our study opens a window for silicon-based photoelectronics through introducing semiconductor-water interfaces.
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Affiliation(s)
- Jidong Li
- Key Laboratory for Intelligent Nano Materials and Devices of the Ministry of Education, State Key Laboratory of Mechanics and Control of Mechanical Structures, Nanjing University of Aeronautics and Astronautics, Nanjing, People's Republic of China
- Institute for Frontier Science, Nanjing University of Aeronautics and Astronautics, Nanjing, People's Republic of China
| | - Yuyang Long
- Key Laboratory for Intelligent Nano Materials and Devices of the Ministry of Education, State Key Laboratory of Mechanics and Control of Mechanical Structures, Nanjing University of Aeronautics and Astronautics, Nanjing, People's Republic of China
| | - Zhili Hu
- Key Laboratory for Intelligent Nano Materials and Devices of the Ministry of Education, State Key Laboratory of Mechanics and Control of Mechanical Structures, Nanjing University of Aeronautics and Astronautics, Nanjing, People's Republic of China
| | - Jiyuan Niu
- Key Laboratory for Intelligent Nano Materials and Devices of the Ministry of Education, State Key Laboratory of Mechanics and Control of Mechanical Structures, Nanjing University of Aeronautics and Astronautics, Nanjing, People's Republic of China
| | - Tiezhu Xu
- Jiangsu Key Laboratory of Electrochemical Energy Storage Technologies, College of Material Science and Engineering, Nanjing University of Aeronautics and Astronautics, Nanjing, People's Republic of China
| | - Maolin Yu
- Key Laboratory for Intelligent Nano Materials and Devices of the Ministry of Education, State Key Laboratory of Mechanics and Control of Mechanical Structures, Nanjing University of Aeronautics and Astronautics, Nanjing, People's Republic of China
| | - Baowen Li
- Key Laboratory for Intelligent Nano Materials and Devices of the Ministry of Education, State Key Laboratory of Mechanics and Control of Mechanical Structures, Nanjing University of Aeronautics and Astronautics, Nanjing, People's Republic of China
| | - Xuemei Li
- Key Laboratory for Intelligent Nano Materials and Devices of the Ministry of Education, State Key Laboratory of Mechanics and Control of Mechanical Structures, Nanjing University of Aeronautics and Astronautics, Nanjing, People's Republic of China
- Jiangsu Key Laboratory of Electrochemical Energy Storage Technologies, College of Material Science and Engineering, Nanjing University of Aeronautics and Astronautics, Nanjing, People's Republic of China
| | - Jianxin Zhou
- Key Laboratory for Intelligent Nano Materials and Devices of the Ministry of Education, State Key Laboratory of Mechanics and Control of Mechanical Structures, Nanjing University of Aeronautics and Astronautics, Nanjing, People's Republic of China
| | - Yanpeng Liu
- Key Laboratory for Intelligent Nano Materials and Devices of the Ministry of Education, State Key Laboratory of Mechanics and Control of Mechanical Structures, Nanjing University of Aeronautics and Astronautics, Nanjing, People's Republic of China
| | - Cheng Wang
- State Key Laboratory of Physical Chemistry of Solid Surfaces, Collaborative Innovation Center of Chemistry for Energy Materials (iChEM), College of Chemistry and Chemical Engineering, Xiamen University, Xiamen, People's Republic of China
| | - Laifa Shen
- Jiangsu Key Laboratory of Electrochemical Energy Storage Technologies, College of Material Science and Engineering, Nanjing University of Aeronautics and Astronautics, Nanjing, People's Republic of China
| | - Wanlin Guo
- Key Laboratory for Intelligent Nano Materials and Devices of the Ministry of Education, State Key Laboratory of Mechanics and Control of Mechanical Structures, Nanjing University of Aeronautics and Astronautics, Nanjing, People's Republic of China.
- Institute for Frontier Science, Nanjing University of Aeronautics and Astronautics, Nanjing, People's Republic of China.
| | - Jun Yin
- Key Laboratory for Intelligent Nano Materials and Devices of the Ministry of Education, State Key Laboratory of Mechanics and Control of Mechanical Structures, Nanjing University of Aeronautics and Astronautics, Nanjing, People's Republic of China.
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24
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Li J, Chen H, Triana CA, Patzke GR. Hematite Photoanodes for Water Oxidation: Electronic Transitions, Carrier Dynamics, and Surface Energetics. Angew Chem Int Ed Engl 2021; 60:18380-18396. [PMID: 33761172 DOI: 10.1002/anie.202101783] [Citation(s) in RCA: 21] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2021] [Indexed: 11/08/2022]
Abstract
We review the current understanding of charge carriers in model hematite photoanodes at different stages. The origin of charge carriers is discussed based on the electronic structure and absorption features, highlighting the controversial assignment of the electronic transitions near the absorption edge. Next, the dynamic evolution of charge carriers is analyzed both on the ultrafast and on the surface reaction timescales, with special emphasis on the arguable spectroscopic assignment of electrons/holes and their kinetics. Further, the competitive charge transfer centers at the solid-liquid interface are reviewed, and the chemical nature of relevant surface states is updated. Finally, an overview on the function of widely employed surface cocatalysts is given to illustrate the complex influence of physiochemical modifications on the charge carrier dynamics. The understanding of charge carriers from their origin all the way to their interfacial transfer is vital for the future of photoanode design.
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Affiliation(s)
- Jingguo Li
- Department of Chemistry, University of Zurich, Winterthurerstrasse 190, CH-8057, Zurich, Switzerland
| | - Hang Chen
- Department of Chemistry, University of Zurich, Winterthurerstrasse 190, CH-8057, Zurich, Switzerland
| | - Carlos A Triana
- Department of Chemistry, University of Zurich, Winterthurerstrasse 190, CH-8057, Zurich, Switzerland
| | - Greta R Patzke
- Department of Chemistry, University of Zurich, Winterthurerstrasse 190, CH-8057, Zurich, Switzerland
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25
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Li J, Chen H, Triana CA, Patzke GR. Hematite Photoanodes for Water Oxidation: Electronic Transitions, Carrier Dynamics, and Surface Energetics. Angew Chem Int Ed Engl 2021. [DOI: 10.1002/ange.202101783] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Affiliation(s)
- Jingguo Li
- Department of Chemistry University of Zurich Winterthurerstrasse 190 CH-8057 Zurich Switzerland
| | - Hang Chen
- Department of Chemistry University of Zurich Winterthurerstrasse 190 CH-8057 Zurich Switzerland
| | - Carlos A. Triana
- Department of Chemistry University of Zurich Winterthurerstrasse 190 CH-8057 Zurich Switzerland
| | - Greta R. Patzke
- Department of Chemistry University of Zurich Winterthurerstrasse 190 CH-8057 Zurich Switzerland
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26
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Laurans M, Wells JAL, Ott S. Immobilising molecular Ru complexes on a protective ultrathin oxide layer of p-Si electrodes towards photoelectrochemical CO 2 reduction. Dalton Trans 2021; 50:10482-10492. [PMID: 34259300 DOI: 10.1039/d1dt01331a] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
Photoelectrochemical CO2 reduction is a promising approach for renewable fuel generation and to reduce greenhouse gas emissions. Owing to their synthetic tunability, molecular catalysts for the CO2 reduction reaction can give rise to high product selectivity. In this context, a RuII complex [Ru(HO-tpy)(6-mbpy)(NCCH3)]2+ (HO-tpy = 4'-hydroxy-2,2':6',2''-terpyridine; 6-mbpy = 6-methyl-2,2'-bipyridine) was immobilised on a thin SiOx layer of a p-Si electrode that was decorated with a bromide-terminated molecular layer. Following the characterisation of the assembled photocathodes by X-ray photoelectron spectroscopy and ellipsometry, PEC experiments demonstrate electron transfer from the p-Si to the Ru complex through the native oxide layer under illumination and a cathodic bias. A state-of-the-art photovoltage of 570 mV was determined by comparison with an analogous n-type Si assembly. While the photovoltage of the modified photocathode is promising for future photoelectrochemical CO2 reduction and the p-Si/SiOx junction seems to be unchanged during the PEC experiments, a fast desorption of the molecular Ru complex was observed. An in-depth investigation of the cathode degradation by comparison with reference materials highlights the role of the hydroxyl functionality of the Ru complex to ensure its grafting on the substrate. In contrast, no essential role for the bromide function on the Si substrate designed to engage with the hydroxyl group of the Ru complex in an SN2-type reaction could be established.
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Affiliation(s)
- Maxime Laurans
- Department of Chemistry - Ångström Laboratory, Uppsala University, Box 523, 75120 Uppsala, Sweden.
| | - Jordann A L Wells
- Department of Chemistry - Ångström Laboratory, Uppsala University, Box 523, 75120 Uppsala, Sweden.
| | - Sascha Ott
- Department of Chemistry - Ångström Laboratory, Uppsala University, Box 523, 75120 Uppsala, Sweden.
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27
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Wang S, Wang T, Liu B, Li H, Feng S, Gong J. Spatial decoupling of light absorption and reaction sites in n-Si photocathodes for solar water splitting. Natl Sci Rev 2021; 8:nwaa293. [PMID: 34691709 PMCID: PMC8363328 DOI: 10.1093/nsr/nwaa293] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2020] [Revised: 12/01/2020] [Accepted: 12/02/2020] [Indexed: 11/13/2022] Open
Abstract
Metal-insulator-semiconductor (MIS) photocathodes offer a simple alternative to p-n junction photocathodes in photoelectrochemical water splitting. However, the parasitic light absorption of catalysts and metal layers in the MIS junction, as well as the lack of low work function metals to form a large band offset with p-Si, severely limit their performance. This paper describes an MIS photocathode fabricated from n-Si, rather than the commonly used p-Si, to spatially decouple light absorption from reaction sites, which enables the majority carriers, instead of the commonly used minority carriers, to drive the surface reaction, making it possible to place the reaction sites far away from the light absorption region. Thus, the catalysts could be moved to the backside of the MIS junction to avoid light shielding. Moreover, the adoption of n-Si unlocks a variety of high work function materials for photovoltage generation. The obtained n-Si MIS photocathode exhibits an applied bias photon-to-current efficiency of 10.26% with a stability up to 300 h.
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Affiliation(s)
- Shujie Wang
- School of Chemical Engineering and Technology, Key Laboratory for Green Chemical Technology of Ministry of Education, Tianjin University, Tianjin 300072, China
- Collaborative Innovation Center of Chemical Science and Engineering (Tianjin), Tianjin 300072, China
| | - Tuo Wang
- School of Chemical Engineering and Technology, Key Laboratory for Green Chemical Technology of Ministry of Education, Tianjin University, Tianjin 300072, China
- Collaborative Innovation Center of Chemical Science and Engineering (Tianjin), Tianjin 300072, China
| | - Bin Liu
- School of Chemical Engineering and Technology, Key Laboratory for Green Chemical Technology of Ministry of Education, Tianjin University, Tianjin 300072, China
- Collaborative Innovation Center of Chemical Science and Engineering (Tianjin), Tianjin 300072, China
| | - Huimin Li
- School of Chemical Engineering and Technology, Key Laboratory for Green Chemical Technology of Ministry of Education, Tianjin University, Tianjin 300072, China
- Collaborative Innovation Center of Chemical Science and Engineering (Tianjin), Tianjin 300072, China
| | - Shijia Feng
- School of Chemical Engineering and Technology, Key Laboratory for Green Chemical Technology of Ministry of Education, Tianjin University, Tianjin 300072, China
- Collaborative Innovation Center of Chemical Science and Engineering (Tianjin), Tianjin 300072, China
| | - Jinlong Gong
- School of Chemical Engineering and Technology, Key Laboratory for Green Chemical Technology of Ministry of Education, Tianjin University, Tianjin 300072, China
- Collaborative Innovation Center of Chemical Science and Engineering (Tianjin), Tianjin 300072, China
- Joint School of National University of Singapore and Tianjin University, International Campus of Tianjin University, Fuzhou 350207, China
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28
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Role of transition-metal electrocatalysts for oxygen evolution with Si-based photoanodes. CHINESE JOURNAL OF CATALYSIS 2021. [DOI: 10.1016/s1872-2067(20)63647-6] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
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29
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Zeng G, Pham TA, Vanka S, Liu G, Song C, Cooper JK, Mi Z, Ogitsu T, Toma FM. Development of a photoelectrochemically self-improving Si/GaN photocathode for efficient and durable H 2 production. NATURE MATERIALS 2021; 20:1130-1135. [PMID: 33820963 DOI: 10.1038/s41563-021-00965-w] [Citation(s) in RCA: 20] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/04/2020] [Accepted: 02/19/2021] [Indexed: 05/26/2023]
Abstract
Development of an efficient yet durable photoelectrode is of paramount importance for deployment of solar-fuel production. Here, we report the photoelectrochemically self-improving behaviour of a silicon/gallium nitride photocathode active for hydrogen production with a Faradaic efficiency approaching ~100%. By using a correlative approach based on different spectroscopic and microscopic techniques, as well as density functional theory calculations, we provide a mechanistic understanding of the chemical transformation that is the origin of the self-improving behaviour. A thin layer of gallium oxynitride forms on the side walls of the gallium nitride grains, via a partial oxygen substitution at nitrogen sites, and displays a higher density of catalytic sites for the hydrogen-evolving reaction. This work demonstrates that the chemical transformation of gallium nitride into gallium oxynitride leads to sustained operation and enhanced catalytic activity, thus showing promise for oxynitride layers as protective catalytic coatings for hydrogen evolution.
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Affiliation(s)
- Guosong Zeng
- Chemical Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, CA, USA
| | - Tuan Anh Pham
- Materials Science Division, Lawrence Livermore National Laboratory, Livermore, CA, USA
| | - Srinivas Vanka
- Department of Electrical Engineering and Computer Science, University of Michigan, Ann Arbor, MI, USA
| | - Guiji Liu
- Chemical Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, CA, USA
| | - Chengyu Song
- National Center for Electron Microscopy, Molecular Foundry, Lawrence Berkeley National Laboratory, Berkeley, CA, USA
| | - Jason K Cooper
- Chemical Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, CA, USA
| | - Zetian Mi
- Department of Electrical Engineering and Computer Science, University of Michigan, Ann Arbor, MI, USA.
| | - Tadashi Ogitsu
- Materials Science Division, Lawrence Livermore National Laboratory, Livermore, CA, USA.
| | - Francesca M Toma
- Chemical Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, CA, USA.
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30
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Scalable, highly stable Si-based metal-insulator-semiconductor photoanodes for water oxidation fabricated using thin-film reactions and electrodeposition. Nat Commun 2021; 12:3982. [PMID: 34172754 PMCID: PMC8233328 DOI: 10.1038/s41467-021-24229-y] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2021] [Accepted: 06/07/2021] [Indexed: 12/02/2022] Open
Abstract
Metal-insulator-semiconductor (MIS) structures are widely used in Si-based solar water-splitting photoelectrodes to protect the Si layer from corrosion. Typically, there is a tradeoff between efficiency and stability when optimizing insulator thickness. Moreover, lithographic patterning is often required for fabricating MIS photoelectrodes. In this study, we demonstrate improved Si-based MIS photoanodes with thick insulating layers fabricated using thin-film reactions to create localized conduction paths through the insulator and electrodeposition to form metal catalyst islands. These fabrication approaches are low-cost and highly scalable, and yield MIS photoanodes with low onset potential, high saturation current density, and excellent stability. By combining this approach with a p+n-Si buried junction, further improved oxygen evolution reaction (OER) performance is achieved with an onset potential of 0.7 V versus reversible hydrogen electrode (RHE) and saturation current density of 32 mA/cm2 under simulated AM1.5G illumination. Moreover, in stability testing in 1 M KOH aqueous solution, a constant photocurrent density of ~22 mA/cm2 is maintained at 1.3 V versus RHE for 7 days. Authors demonstrate Si-based MIS photoanodes using Al thin-film reactions to create localized conduction paths through the insulator and Ni electrodeposition to form metal catalyst islands. These approaches yielded low onset potential, high saturation current density, and excellent stability.
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31
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Hemmerling JR, Mathur A, Linic S. Design Principles for Efficient and Stable Water Splitting Photoelectrocatalysts. Acc Chem Res 2021; 54:1992-2002. [PMID: 33794089 DOI: 10.1021/acs.accounts.1c00072] [Citation(s) in RCA: 23] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
ConspectusPhotoelectrochemical water splitting is a promising avenue for sustainable production of hydrogen used in the chemical industry and hydrogen fuel cells. The basic components of most photoelectrochemical water splitting systems are semiconductor light absorbers coupled to electrocatalysts, which perform the desired chemical reactions. A critical challenge for the design of these systems is the lack of stability for the majority of desired semiconductors under operating water splitting conditions. One strategy to address this issue is to protect the semiconductor by covering it with a stabilizing insulator layer, creating a metal-insulator-semiconductor (MIS) architecture, which has demonstrated improved stability. In addition to enhanced stability, the insulator layer may significantly affect the electron and hole transfer, which governs the recombination rates. Furthermore, the insertion of an insulator layer leads to the introduction of additional insulator/electrocatalyst and insulator/semiconductor interfaces. These interfaces can impact the system's performance significantly, and they need to be carefully engineered to optimize the efficiencies of MIS systems. In this Account, we describe our recent progress in shedding light on the critical role of the insulator and the interfaces on the performance of MIS systems. We discuss our findings by focusing on the concrete example of planar n-type Si protected by a HfO2 insulator layer and coupled to a Ni or Ir electrocatalyst that performs the oxygen evolution reaction, one of the water splitting half-reactions. To improve our fundamental understanding of the insulator layer, we precisely control the HfO2 insulator thickness using atomic layer deposition (ALD), and we perform a series of rigorous electrochemical experiments coupled with theory and modeling. We demonstrate that by tuning the insulator thickness, we can control the flux and recombination of photogenerated electrons and holes to optimize the generated photovoltage. Despite optimizing the thickness, we find that the maximum generated photovoltage in MIS systems is often significantly lower than the upper performance limit, i.e., there are additional losses in the system that could not be addressed by optimizing the insulator thickness. We identify the sources of these losses and describe strategies to minimize them by a combination of improving the semiconductor light absorption, removing nonidealities associated with interfacial defects, and finding alternative insulators with improved charge carrier selectivity. Finally, we quantify the improvements that can be obtained by implementing these specific strategies. Our collective work outlines strategies to analyze MIS systems, identify the sources of efficiency losses, and optimize the design to approach the fundamental performance limits. These general approaches are broadly applicable to photoelectrochemical materials that utilize sunlight to produce value-added chemicals.
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Affiliation(s)
- John R. Hemmerling
- Department of Chemical Engineering, University of Michigan, Ann Arbor, Michigan 48109, United States
- Catalysis Science and Technology Institute, University of Michigan, Ann Arbor, Michigan 48109, United States
| | - Aarti Mathur
- Department of Chemical Engineering, University of Michigan, Ann Arbor, Michigan 48109, United States
- Catalysis Science and Technology Institute, University of Michigan, Ann Arbor, Michigan 48109, United States
| | - Suljo Linic
- Department of Chemical Engineering, University of Michigan, Ann Arbor, Michigan 48109, United States
- Catalysis Science and Technology Institute, University of Michigan, Ann Arbor, Michigan 48109, United States
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32
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Oh K, de Sagazan O, Léon C, Le Gall S, Loget G. Custom plating of nanoscale semiconductor/catalyst junctions for photoelectrochemical water splitting. NANOSCALE 2021; 13:1997-2004. [PMID: 33443521 DOI: 10.1039/d0nr08414j] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
Photoelectrochemical water splitting under harsh chemical conditions can be promoted by dispersed transition metal nanoparticles electrodeposited on n-Si surfaces, without the need for classical protection layers. Although this method is simple, it only allows for poor control of metal morphology and geometry on the photoanode surface. Herein, we introduce templated nanoscale electrodeposition on photoactive n-Si for the customization of nanoscale inhomogeneous Schottky junctions and demonstrate their use as stable photoanodes. The photoelectrochemical properties of the so-manufactured photoanodes exhibit a strong dependence on the photoanodes' geometrical features, and the obtained experimental trends are rationalized using simulation.
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Affiliation(s)
- Kiseok Oh
- Univ Rennes, CNRS, ISCR (Institut des Sciences Chimiques de Rennes)-UMR6226, F-35000 Rennes, France.
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33
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Wang D, Liu X, Fang S, Huang C, Kang Y, Yu H, Liu Z, Zhang H, Long R, Xiong Y, Lin Y, Yue Y, Ge B, Ng TK, Ooi BS, Mi Z, He JH, Sun H. Pt/AlGaN Nanoarchitecture: Toward High Responsivity, Self-Powered Ultraviolet-Sensitive Photodetection. NANO LETTERS 2021; 21:120-129. [PMID: 33320006 DOI: 10.1021/acs.nanolett.0c03357] [Citation(s) in RCA: 43] [Impact Index Per Article: 14.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
Energy-saving photodetectors are the key components in future photonic systems. Particularly, self-powered photoelectrochemical-type photodetectors (PEC-PDs), which depart completely from the classical solid-state junction device, have lately intrigued intensive interest to meet next-generation power-independent and environment-sensitive photodetection. Herein, we construct, for the first time, solar-blind PEC PDs based on self-assembled AlGaN nanostructures on silicon. Importantly, with the proper surface platinum (Pt) decoration, a significant boost of photon responsivity by more than an order of magnitude was achieved in the newly built Pt/AlGaN nanoarchitectures, demonstrating strikingly high responsivity of 45 mA/W and record fast response/recovery time of 47/20 ms without external power source. Such high solar-blind photodetection originates from the unparalleled material quality, fast interfacial kinetics, as well as high carrier separation efficiency which suggests that embracement of defect-free wide-bandgap semiconductor nanostructures with appropriate surface decoration offers an unprecedented opportunity for designing future energy-efficient and large-scale optoelectronic systems on a silicon platform.
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Affiliation(s)
- Danhao Wang
- School of Microelectronics, University of Science and Technology of China, Hefei 230029, P.R. China
| | - Xin Liu
- School of Microelectronics, University of Science and Technology of China, Hefei 230029, P.R. China
| | - Shi Fang
- School of Microelectronics, University of Science and Technology of China, Hefei 230029, P.R. China
| | - Chen Huang
- School of Microelectronics, University of Science and Technology of China, Hefei 230029, P.R. China
| | - Yang Kang
- School of Microelectronics, University of Science and Technology of China, Hefei 230029, P.R. China
| | - Huabin Yu
- School of Microelectronics, University of Science and Technology of China, Hefei 230029, P.R. China
| | - Zhongling Liu
- School of Microelectronics, University of Science and Technology of China, Hefei 230029, P.R. China
| | - Haochen Zhang
- School of Microelectronics, University of Science and Technology of China, Hefei 230029, P.R. China
| | - Ran Long
- School of Chemistry and Materials Science, University of Science and Technology of China, Hefei 230029, P.R. China
| | - Yujie Xiong
- School of Chemistry and Materials Science, University of Science and Technology of China, Hefei 230029, P.R. China
| | - Yangjian Lin
- Institute of Physical Science and Information Technology, Anhui University, Hefei 230029, P.R. China
| | - Yang Yue
- Institute of Physical Science and Information Technology, Anhui University, Hefei 230029, P.R. China
| | - Binghui Ge
- Institute of Physical Science and Information Technology, Anhui University, Hefei 230029, P.R. China
| | - Tien Khee Ng
- Computer, Electrical, and Mathematical Sciences, and Engineering Division, King Abdullah University of Science and Technology, Thuwal 23955-6900, Saudi Arabia
| | - Boon S Ooi
- Computer, Electrical, and Mathematical Sciences, and Engineering Division, King Abdullah University of Science and Technology, Thuwal 23955-6900, Saudi Arabia
| | - Zetian Mi
- Department of Electrical Engineering and Computer Science, University of Michigan, 1301 Beal Avenue, Ann Arbor, Michigan 48109, United States
| | - Jr-Hau He
- Department of Materials Science and Engineering, City University of Hong Kong, Kowloon, Hong Kong SAR 999077, P.R. China
| | - Haiding Sun
- School of Microelectronics, University of Science and Technology of China, Hefei 230029, P.R. China
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34
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Li J, Wan W, Triana CA, Chen H, Zhao Y, Mavrokefalos CK, Patzke GR. Reaction kinetics and interplay of two different surface states on hematite photoanodes for water oxidation. Nat Commun 2021; 12:255. [PMID: 33431853 PMCID: PMC7801602 DOI: 10.1038/s41467-020-20510-8] [Citation(s) in RCA: 34] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2020] [Accepted: 11/30/2020] [Indexed: 11/09/2022] Open
Abstract
Understanding the function of surface states on photoanodes is crucial for unraveling the underlying reaction mechanisms of water oxidation. For hematite photoanodes, only one type of surface states with higher oxidative energy (S1) has been proposed and verified as reaction intermediate, while the other surface state located at lower potentials (S2) was assigned to inactive or recombination sites. Through employing rate law analyses and systematical (photo)electrochemical characterizations, here we show that S2 is an active reaction intermediate for water oxidation as well. Furthermore, we demonstrate that the reaction kinetics and dynamic interactions of both S1 and S2 depend significantly on operational parameters, such as illumination intensity, nature of the electrolyte, and applied potential. These insights into the individual reaction kinetics and the interplay of both surface states are decisive for designing efficient photoanodes.
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Affiliation(s)
- Jingguo Li
- Department of Chemistry, University of Zurich, Winterthurerstrasse 190, CH-8057, Zurich, Switzerland
| | - Wenchao Wan
- Department of Chemistry, University of Zurich, Winterthurerstrasse 190, CH-8057, Zurich, Switzerland
| | - Carlos A Triana
- Department of Chemistry, University of Zurich, Winterthurerstrasse 190, CH-8057, Zurich, Switzerland
| | - Hang Chen
- Department of Chemistry, University of Zurich, Winterthurerstrasse 190, CH-8057, Zurich, Switzerland
| | - Yonggui Zhao
- Department of Chemistry, University of Zurich, Winterthurerstrasse 190, CH-8057, Zurich, Switzerland
| | - Christos K Mavrokefalos
- Department of Chemistry, University of Zurich, Winterthurerstrasse 190, CH-8057, Zurich, Switzerland
| | - Greta R Patzke
- Department of Chemistry, University of Zurich, Winterthurerstrasse 190, CH-8057, Zurich, Switzerland.
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35
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Zhang M, Chu X, Zhang H, Huang F, Liu P, Li S. Interface engineering of a hierarchical Zn xCd 1-xS architecture with favorable kinetics for high-performance solar water splitting. Phys Chem Chem Phys 2021; 23:9347-9356. [PMID: 33885073 DOI: 10.1039/d0cp06489k] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Manipulating the charge carrier transport in photoactive materials is a big challenge toward high efficiency solar water splitting. Herein, we designed a hierarchical ZnxCd1-xS architecture for tuning the interfacial charge transfer kinetics. The in situ growth of ZnxCd1-xS nanoflakes on ZnO backbones provided low interfacial resistance for charge separation. With this special configuration, the optimized Zn0.33Cd0.67S photoanode achieved significantly enhanced performance with a photocurrent density of 10.67 mA cm-2 at 1.23 V versus RHE under AM1.5G solar light irradiation, which is about 14.1 and 2.5 times higher than that of the pristine ZnO and CdS nanoparticle decorated ZnO photoanodes, respectively. After coating a thin SiO2 layer, the photostability of the hierarchical Zn0.33Cd0.67S photoanode is greatly enhanced with 92.33% of the initial value retained under 3600 s continuous light illumination. The prominent PEC activity of the hierarchical ZnxCd1-xS nanorod arrays can be ascribed to an enhanced charge transfer rate aroused by the binder-free interfacial heterojunction, and the improved reaction kinetics at the electrode-electrolyte interface, which is evidenced by electrochemically active surface area measurements and intensity modulated photocurrent spectroscopy analysis. This interfacial heterojunction strategy provides a promising pathway to prepare high performance photoelectrodes.
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Affiliation(s)
- Miaomiao Zhang
- AnHui Province Key Laboratory of Chemistry for Inorganic/Organic Hybrid Functionalized Materials, Key Laboratory of Structure and Functional Regulation of Hybrid Materials (Anhui University) Ministry of Education, School of Chemistry and Chemical Engineering, School of Physics and Materials Science, Institute of Physical Science and Information Technology, Anhui University, Hefei, 230601, P. R. China.
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36
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Guo Z, Ambrosio F, Pasquarello A. Evaluation of Photocatalysts for Water Splitting through Combined Analysis of Surface Coverage and Energy-Level Alignment. ACS Catal 2020. [DOI: 10.1021/acscatal.0c03006] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Zhendong Guo
- Chaire de Simulation à l’Echelle Atomique (CSEA), Ecole Polytechnique Fédérale de Lausanne (EPFL), CH-1015 Lausanne, Switzerland
| | - Francesco Ambrosio
- Chaire de Simulation à l’Echelle Atomique (CSEA), Ecole Polytechnique Fédérale de Lausanne (EPFL), CH-1015 Lausanne, Switzerland
| | - Alfredo Pasquarello
- Chaire de Simulation à l’Echelle Atomique (CSEA), Ecole Polytechnique Fédérale de Lausanne (EPFL), CH-1015 Lausanne, Switzerland
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37
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Li S, She G, Xu J, Zhang S, Zhang H, Mu L, Ge C, Jin K, Luo J, Shi W. Metal Silicidation in Conjunction with Dopant Segregation: A Promising Strategy for Fabricating High-Performance Silicon-Based Photoanodes. ACS APPLIED MATERIALS & INTERFACES 2020; 12:39092-39097. [PMID: 32805824 DOI: 10.1021/acsami.0c09498] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
Silicon (Si)-based Schottky junction photoelectrodes have attracted considerable attention for photoelectrochemical (PEC) water splitting in recent years. To realize highly efficient Si-based Schottky junction photoelectrodes, the critical challenge is to enable the photoelectrodes to not only have a high Schottky barrier height (SBH), by which a high photovoltage can be obtained, but also ensure an efficient charge transport. Here, we propose and demonstrate a strategy to fabricate a high-performance NiSi/n-Si Schottky junction photoanode by metal silicidation in conjunction with dopant segregation (DS). The metal silicidation produces photoanodes with a high-quality NiSi/Si interface without a disordered SiO2 layer, which ensures highly efficient charge transport, and thus a high saturated photocurrent density of 33 mA cm-2 was attained for the photoanode. The subsequent DS gives the photoanodes a high SBH of 0.94 eV through the introduction of electric dipoles at the NiSi/n-Si interface. As a result, a high photovoltage and favorable onset potential of 1.03 V vs RHE was achieved. In addition, the strong alkali corrosion resistance of NiSi also endows the photoanode with a high stability during PEC operation in 1 M KOH. Our work provides a universal strategy to fabricate metal-silicide/Si Schottky junction photoelectrodes for high-performance PEC water splitting.
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Affiliation(s)
- Shengyang Li
- Key Laboratory of Photochemical Conversion and Optoelectronic Materials, Technical Institute of Physics and Chemistry, Chinese Academy of Sciences, Beijing 100190, China
- University of Chinese Academy of Sciences, Chinese Academy of Sciences, Beijing 100049, China
| | - Guangwei She
- Key Laboratory of Photochemical Conversion and Optoelectronic Materials, Technical Institute of Physics and Chemistry, Chinese Academy of Sciences, Beijing 100190, China
| | - Jing Xu
- Key Laboratory of Microelectronic Devices & Integrated Technology, Institute of Microelectronics, Chinese Academy of Sciences, Beijing 100029, China
| | - Shaoyang Zhang
- Key Laboratory of Photochemical Conversion and Optoelectronic Materials, Technical Institute of Physics and Chemistry, Chinese Academy of Sciences, Beijing 100190, China
- University of Chinese Academy of Sciences, Chinese Academy of Sciences, Beijing 100049, China
| | - Haoyue Zhang
- Key Laboratory of Photochemical Conversion and Optoelectronic Materials, Technical Institute of Physics and Chemistry, Chinese Academy of Sciences, Beijing 100190, China
- University of Chinese Academy of Sciences, Chinese Academy of Sciences, Beijing 100049, China
| | - Lixuan Mu
- Key Laboratory of Photochemical Conversion and Optoelectronic Materials, Technical Institute of Physics and Chemistry, Chinese Academy of Sciences, Beijing 100190, China
| | - Chen Ge
- Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China
| | - Kuijuan Jin
- Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China
| | - Jun Luo
- University of Chinese Academy of Sciences, Chinese Academy of Sciences, Beijing 100049, China
- Key Laboratory of Microelectronic Devices & Integrated Technology, Institute of Microelectronics, Chinese Academy of Sciences, Beijing 100029, China
| | - Wensheng Shi
- Key Laboratory of Photochemical Conversion and Optoelectronic Materials, Technical Institute of Physics and Chemistry, Chinese Academy of Sciences, Beijing 100190, China
- University of Chinese Academy of Sciences, Chinese Academy of Sciences, Beijing 100049, China
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38
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Zhang P, Wang W, Wang H, Li Y, Cui C. Tuning Hole Accumulation of Metal Oxides Promotes the Oxygen Evolution Rate. ACS Catal 2020. [DOI: 10.1021/acscatal.0c02882] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
Affiliation(s)
| | - Wei Wang
- School of Materials and Energy, University of Electronic Science and Technology of China, Chengdu 610054, China
| | - Hui Wang
- Analytical & Testing Center, Sichuan University, Chengdu 610065, China
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Lan G, Nong J, Wei W, Liu X, Luo P, Jin W, Wei D, Wei D. Highly stable all-in-one photoelectrochemical electrodes based on carbon nanowalls. NANOTECHNOLOGY 2020; 31:335401. [PMID: 32330907 DOI: 10.1088/1361-6528/ab8cf5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
Photoelectrochemical (PEC) cells offer a promising approach for developing low-cost solar energy conversion systems. However, the lack of stable and cost-effective electrodes remains a bottleneck that hampers their practical applications. Here, we propose a kind of integrated all-in-one three-dimensional (3D) carbon nanowall (CNW) electrode without sensitized semiconductors for stable all-carbon PEC cells. The all-in-one CNW electrodes were fabricated by directly growing CNW on both sides of the SiO2/Si/SiO2 wafer employing the radio frequency plasmon enhanced chemical vapor deposition method. Benefitting from the interconnected 3D textured structure, the CNW can effectively absorb the incident light and provide a large electrochemical reaction interface at the CNW surface that promotes the separation of photogenerated charge carriers, which makes it a superior electrode material. Experimental results show that the all-in-one CNW electrodes possess excellent PEC performance with a photocurrent density of 830 μA cm-2. Moreover, the CNW electrodes exhibit excellent photoresponses over a wide waveband and superior stability with a maintained photocurrent response, even after 60 d, which outperforms the electrodes using the other two-dimensional layered materials or semiconductor sensitized electrodes. Such an all-in-one electrode with impressive photovoltaic properties provides a promising platform for PEC applications that is eco-friendly with high efficiency, excellent stability and low cost.
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Affiliation(s)
- Guilian Lan
- Key Laboratory of Optoelectronic Technology & Systems, Ministry of Education of China, College of Optoelectronic Engineering, Chongqing University, Chongqing 400044, People's Republic of China. Chongqing Key Laboratory of Multi-scale Manufacturing Technology, Chongqing Institute of Green and Intelligent Technology, Chinese Academy of Sciences, Chongqing 400714, People's Republic of China
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40
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Terrero Rodríguez IM, Borrill AJ, Schaffer KJ, Hernandez JB, O’Neil GD. Light-Addressable Electrochemical Sensing with Electrodeposited n-Silicon/Gold Nanoparticle Schottky Junctions. Anal Chem 2020; 92:11444-11452. [DOI: 10.1021/acs.analchem.0c02512] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Affiliation(s)
- Irina M. Terrero Rodríguez
- Department of Chemistry and Biochemistry, Montclair State University, Montclair, New Jersey 07043, United States
| | - Alexandra J. Borrill
- Department of Chemistry and the Centre for Doctoral Training in Diamond Science and Technology, University of Warwick, Coventry, CV4 7AL, United Kingdom
| | - Katherine J. Schaffer
- Department of Chemistry and Biochemistry, Montclair State University, Montclair, New Jersey 07043, United States
| | - Jocelyn B. Hernandez
- Department of Chemistry and Biochemistry, Montclair State University, Montclair, New Jersey 07043, United States
| | - Glen D. O’Neil
- Department of Chemistry and Biochemistry, Montclair State University, Montclair, New Jersey 07043, United States
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41
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Liang J, Chen D, Yao X, Zhang K, Qu F, Qin L, Huang Y, Li J. Recent Progress and Development in Inorganic Halide Perovskite Quantum Dots for Photoelectrochemical Applications. SMALL (WEINHEIM AN DER BERGSTRASSE, GERMANY) 2020; 16:e1903398. [PMID: 31583803 DOI: 10.1002/smll.201903398] [Citation(s) in RCA: 48] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/30/2019] [Revised: 08/23/2019] [Indexed: 06/10/2023]
Abstract
Inorganic halide perovskite quantum dots (IHPQDs) have recently emerged as a new class of optoelectronic nanomaterials that can outperform the existing hybrid organometallic halide perovskite (OHP), II-VI and III-V groups semiconductor nanocrystals, mainly due to their relatively high stability, excellent photophysical properties, and promising applications in wide-ranging and diverse fields. In particular, IHPQDs have attracted much recent attention in the field of photoelectrochemistry, with the potential to harness their superb optical and charge transport properties as well as spectacular characteristics of quantum confinement effect for opening up new opportunities in next-generation photoelectrochemical (PEC) systems. Over the past few years, numerous efforts have been made to design and prepare IHPQD-based materials for a wide range of applications in photoelectrochemistry, ranging from photocatalytic degradation, photocatalytic CO2 reduction and PEC sensing, to photovoltaic devices. In this review, the recent advances in the development of IHPQD-based materials are summarized from the standpoint of photoelectrochemistry. The prospects and further developments of IHPQDs in this exciting field are also discussed.
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Affiliation(s)
- Junhui Liang
- College of Materials Science and Engineering, China Jiliang University, Hangzhou, 310018, Zhejiang, China
| | - Da Chen
- College of Materials Science and Engineering, China Jiliang University, Hangzhou, 310018, Zhejiang, China
| | - Xin Yao
- College of Optical and Electronic Technology, China Jiliang University, Hangzhou, 310018, Zhejiang, China
| | - Kaixiang Zhang
- Department of Chemistry, Key Laboratory of Bioorganic Phosphorus Chemistry & Chemical Biology, Tsinghua University, Beijing, 100084, China
- School of Pharmaceutical Sciences, Zhengzhou University, Zhengzhou, 450001, China
| | - Fengli Qu
- College of Chemistry and Chemical Engineering, Qufu Normal University, Qufu, 273165, Shandong, China
| | - Laishun Qin
- College of Materials Science and Engineering, China Jiliang University, Hangzhou, 310018, Zhejiang, China
| | - Yuexiang Huang
- College of Materials Science and Engineering, China Jiliang University, Hangzhou, 310018, Zhejiang, China
| | - Jinghong Li
- Department of Chemistry, Key Laboratory of Bioorganic Phosphorus Chemistry & Chemical Biology, Tsinghua University, Beijing, 100084, China
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42
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Cushing SK, Porter IJ, de Roulet BR, Lee A, Marsh BM, Szoke S, Vaida ME, Leone SR. Layer-resolved ultrafast extreme ultraviolet measurement of hole transport in a Ni-TiO 2-Si photoanode. SCIENCE ADVANCES 2020; 6:eaay6650. [PMID: 32284972 PMCID: PMC7124930 DOI: 10.1126/sciadv.aay6650] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/08/2019] [Accepted: 01/08/2020] [Indexed: 05/30/2023]
Abstract
Metal oxide semiconductor junctions are central to most electronic and optoelectronic devices, but ultrafast measurements of carrier transport have been limited to device-average measurements. Here, charge transport and recombination kinetics in each layer of a Ni-TiO2-Si junction is measured using the element specificity of broadband extreme ultraviolet (XUV) ultrafast pulses. After silicon photoexcitation, holes are inferred to transport from Si to Ni ballistically in ~100 fs, resulting in characteristic spectral shifts in the XUV edges. Meanwhile, the electrons remain on Si. After picoseconds, the transient hole population on Ni is observed to back-diffuse through the TiO2, shifting the Ti spectrum to a higher oxidation state, followed by electron-hole recombination at the Si-TiO2 interface and in the Si bulk. Electrical properties, such as the hole diffusion constant in TiO2 and the initial hole mobility in Si, are fit from these transient spectra and match well with values reported previously.
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Affiliation(s)
- Scott K. Cushing
- Division of Chemistry and Chemical Engineering, California Institute of Technology, Pasadena, CA 91125, USA
| | - Ilana J. Porter
- Department of Chemistry, University of California, Berkeley, Berkeley, CA 94720, USA
- Chemical Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, CA 94720, USA
| | - Bethany R. de Roulet
- Department of Chemistry, University of California, Berkeley, Berkeley, CA 94720, USA
| | - Angela Lee
- Department of Chemistry, University of California, Berkeley, Berkeley, CA 94720, USA
| | - Brett M. Marsh
- Department of Chemistry, University of California, Berkeley, Berkeley, CA 94720, USA
| | - Szilard Szoke
- Division of Chemistry and Chemical Engineering, California Institute of Technology, Pasadena, CA 91125, USA
| | - Mihai E. Vaida
- Department of Chemistry, University of California, Berkeley, Berkeley, CA 94720, USA
- Department of Physics, University of Central Florida, Orlando, FL 32816, USA
| | - Stephen R. Leone
- Department of Chemistry, University of California, Berkeley, Berkeley, CA 94720, USA
- Chemical Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, CA 94720, USA
- Department of Physics, University of California, Berkeley, Berkeley, CA 94720, USA
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43
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Ben-Naim M, Palm DW, Strickler AL, Nielander AC, Sanchez J, King LA, Higgins DC, Jaramillo TF. A Spin Coating Method To Deposit Iridium-Based Catalysts onto Silicon for Water Oxidation Photoanodes. ACS APPLIED MATERIALS & INTERFACES 2020; 12:5901-5908. [PMID: 31971770 DOI: 10.1021/acsami.9b20099] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
Silicon has shown promise for use as a small band gap (1.1 eV) absorber material in photoelectrochemical (PEC) water splitting. However, the limited stability of silicon in acidic electrolyte requires the use of protection strategies coupled with catalysts. Herein, spin coating is used as a versatile method to directly coat silicon photoanodes with an IrOx oxygen evolution reaction (OER) catalyst, reducing the processing complexity compared to conventional fabrication schemes. Biphasic strontium chloride/iridium oxide (SrCl2:IrOx) catalysts are also developed, and both catalysts form photoactive junctions with silicon and demonstrate high photoanode activity. The iridium oxide photoanode displays a photocurrent onset at 1.06 V vs reversible hydrogen electrode (RHE), while the SrCl2:IrOx photoanode onsets earlier at 0.96 V vs RHE. The differing potentials are consistent with the observed photovoltages of 0.43 and 0.53 V for the IrOx and SrCl2:IrOx, respectively. By measuring the oxidation of a reversible redox couple, Fe(CN)63-/4-, we compare the charge carrier extraction of the devices and show that the addition of SrCl2 to the IrOx catalyst improves the silicon-electrolyte interface compared to pure IrOx. However, the durability of the strontium-containing photoanode remains a challenge, with its photocurrent density decreasing by 90% over 4 h. The IrOx photoanode, on the other hand, maintained a stable photocurrent density over this timescale. Characterization of the as-prepared and post-tested material structure via Auger electron spectroscopy identifies catalyst film cracking and delamination as the primary failure modes. We propose that improvements to catalyst adhesion should further the viability of spin coating as a technique for photoanode preparation.
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Affiliation(s)
- Micha Ben-Naim
- Department of Chemical Engineering , Stanford University , 443 Via Ortega, Stanford California 94305 , United States
| | - David W Palm
- Department of Chemical Engineering , Stanford University , 443 Via Ortega, Stanford California 94305 , United States
| | - Alaina L Strickler
- Department of Chemical Engineering , Stanford University , 443 Via Ortega, Stanford California 94305 , United States
| | - Adam C Nielander
- Department of Chemical Engineering , Stanford University , 443 Via Ortega, Stanford California 94305 , United States
| | - Joel Sanchez
- Department of Chemical Engineering , Stanford University , 443 Via Ortega, Stanford California 94305 , United States
| | - Laurie A King
- Department of Chemical Engineering , Stanford University , 443 Via Ortega, Stanford California 94305 , United States
- Faculty of Science and Engineering , Manchester Metropolitan University , Chester Street , Manchester M1 5GD , U.K
| | - Drew C Higgins
- Department of Chemical Engineering , Stanford University , 443 Via Ortega, Stanford California 94305 , United States
- Department of Chemical Engineering , McMaster University , Hamilton Ontario , Canada L8S 4L8
| | - Thomas F Jaramillo
- Department of Chemical Engineering , Stanford University , 443 Via Ortega, Stanford California 94305 , United States
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Fengler S, Kriegel H, Schieda M, Gutzmann H, Klassen T, Wollgarten M, Dittrich T. Charge Transfer in c-Si(n ++)/TiO 2(ALD) at the Amorphous/Anatase Transition: A Transient Surface Photovoltage Spectroscopy Study. ACS APPLIED MATERIALS & INTERFACES 2020; 12:3140-3149. [PMID: 31829545 DOI: 10.1021/acsami.9b17592] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
Electronic properties and charge transfer processes were studied in an n-Si(n++)/TiO2(ALD) system at an amorphous TiO2/anatase transition by transient surface photovoltage spectroscopy at constant photon flux. The TiO2 layers were deposited by atomic layer deposition (ALD) onto highly doped silicon (c-Si(n++)), and the phase composition of the TiO2 layers changed with increasing thickness from amorphous to the anatase polymorph as anatase crystallites started to grow at the surface. Depending on phase composition, the band gap of TiO2 correlated with the characteristic energy of exponential tails. In most cases, photogenerated electrons were separated toward the back contact. For photogeneration in c-Si(n++), electron back transfer was limited by Auger recombination with holes in the surface space charge region of c-Si(n++), and by electron transfer across the interface, either via exponentially distributed states near the conduction band edge of amorphous TiO2 or via distance-dependent recombination with holes trapped in anatase. For photogeneration in TiO2, electron back transfer was limited by trapping in TiO2. Under strong light absorption in amorphous TiO2 with anatase crystallites on top, electrons were preferentially separated toward the TiO2 surface.
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Affiliation(s)
- Steffen Fengler
- Helmholtz-Zentrum Geesthacht, Centre for Materials and Coastal Research GmbH , Max-Planck-Str. 1 , D-21502 Geesthacht , Germany
| | - Herman Kriegel
- Helmholtz-Zentrum Geesthacht, Centre for Materials and Coastal Research GmbH , Max-Planck-Str. 1 , D-21502 Geesthacht , Germany
| | - Mauricio Schieda
- Helmholtz-Zentrum Geesthacht, Centre for Materials and Coastal Research GmbH , Max-Planck-Str. 1 , D-21502 Geesthacht , Germany
| | - Henning Gutzmann
- University of the Federal Armed Forces , Helmut-Schmidt-University , Holstenhofweg 85 , D-22043 Hamburg , Germany
| | - Thomas Klassen
- University of the Federal Armed Forces , Helmut-Schmidt-University , Holstenhofweg 85 , D-22043 Hamburg , Germany
| | - Markus Wollgarten
- Helmholtz-Zentrum Berlin für Materialien und Energie GmbH , Hahn-Meitner-Platz 1 , D-14109 Berlin , Germany
| | - Thomas Dittrich
- Helmholtz-Zentrum Berlin für Materialien und Energie GmbH , Institut für Silizium-Photovoltaik , Kekuléstr. 5 , D-12489 Berlin , Germany
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45
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Jung JY, Kim SH, Shinde SS, Kim DH, Lin C, Lee JH. A semiconductor junction photoelectrochemical device without a depletion region. NANOSCALE 2019; 11:23013-23020. [PMID: 31769774 DOI: 10.1039/c9nr08172k] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
Semiconductor junctions are believed to form a depletion region at the band edge of the semiconductor as the chemical potentials for electrons (work functions) are aligned to the same level. Here, we demonstrated that ultrathin Ni film (less than 4 nm thick)/Si junction-based photoelectrochemical (PEC) devices have no depletion region due to three distinct phenomena: (i) the electrostatic or electrochemical potential extrinsically charged to the electrolytic-capacitive Ni surface dominates rather than the chemical potential of electrons (work function) of the bulk Ni, (ii) the charged potential is dynamically variable depending on the reaction and is rapidly volatile so as not to be constant; therefore, (iii) the charged potential is misaligned with the chemical potential of Si under equivalent circuit conditions. Such junction PEC devices were shown to follow a novel operating principle in which the output voltage (open circuit potential) is generated by the electrochemical potential charged at the Ni surface, and not by the light-induced potential (photovoltage) in Si. In addition, due to the bipolar charging nature, the ultrathin Ni film was effective in achieving a high open circuit potential in both p-Si photocathodes (0.57 V) and n-Si photoanodes (0.45 V). These anomalous results were not explained by the classical Schottky diode model based on the equilibrium of diffusion-drift current but by establishing a new model based on the equilibrium of the diffusion-charging current without accounting for the depletion region. Our findings provide an explanation for the unexpected results of the nanostructured PEC devices and insight into a new design that can overcome conventional limitations.
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Affiliation(s)
- Jin-Young Jung
- Department of Materials Science and Chemical Engineering, Hanyang University, 55 Hanyangdaehak-ro, Sangnok-gu, Ansan, Kyeonggi-do 15588, Republic of Korea.
| | - Sung-Hae Kim
- Department of Materials Science and Chemical Engineering, Hanyang University, 55 Hanyangdaehak-ro, Sangnok-gu, Ansan, Kyeonggi-do 15588, Republic of Korea.
| | - Sambhaji S Shinde
- Department of Materials Science and Chemical Engineering, Hanyang University, 55 Hanyangdaehak-ro, Sangnok-gu, Ansan, Kyeonggi-do 15588, Republic of Korea.
| | - Dong-Hyung Kim
- Department of Materials Science and Chemical Engineering, Hanyang University, 55 Hanyangdaehak-ro, Sangnok-gu, Ansan, Kyeonggi-do 15588, Republic of Korea.
| | - Chao Lin
- Department of Materials Science and Chemical Engineering, Hanyang University, 55 Hanyangdaehak-ro, Sangnok-gu, Ansan, Kyeonggi-do 15588, Republic of Korea.
| | - Jung-Ho Lee
- Department of Materials Science and Chemical Engineering, Hanyang University, 55 Hanyangdaehak-ro, Sangnok-gu, Ansan, Kyeonggi-do 15588, Republic of Korea.
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46
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Liu Y, Smith RDL. Identifying protons trapped in hematite photoanodes through structure-property analysis. Chem Sci 2019; 11:1085-1096. [PMID: 34084364 PMCID: PMC8145353 DOI: 10.1039/c9sc04853g] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023] Open
Abstract
Uncertainty regarding the nature of structural defects in hematite and their specific impacts on material properties and photoelectrocatalytic water oxidation inhibits their development as photoanodes. We perform structure–property analysis on a series of hematite films fabricated by annealing lepidocrocite films with varied temperatures, annealing times and atmospheres and find a gradient in the magnitude of a crystal lattice distortion by tracking the relative intensity of a formally Raman inactive vibrational mode. Structure–property analysis reveals that this feature in the Raman spectrum correlates to photocurrent density, semiconductor band positions, and the onset of photoelectrocatalysis. We propose that the onset of photoelectrocatalysis is linked to the location of defects that act as intraband recombination sites; an increase in the degree of structural distortion shifts these states towards the conduction band, thereby facilitating recombination. Analysis of the nature of the key Raman vibrations, X-ray diffraction patterns, and the synthetic conditions leads us to assign the distortion to iron vacancies that are induced by the trapping of protons within the crystal lattice. The ability to rapidly diagnose a specific structural defect will aid in the optimization of fabrication protocols for hematite photoanodes. Features in Raman spectra are found to correlate to the band structure and photoelectrochemical behavior across a series of hematite photoanodes. Analysis suggests the presence of iron vacancies caused by the trapping of interstitial protons.![]()
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Affiliation(s)
- Yutong Liu
- Department of Chemistry, University of Waterloo 200 University Avenue W. Waterloo Ontario N2L 3G1 Canada
| | - Rodney D L Smith
- Department of Chemistry, University of Waterloo 200 University Avenue W. Waterloo Ontario N2L 3G1 Canada .,Waterloo Institute for Nanotechnology, University of Waterloo 200 University Avenue W. Waterloo Ontario N2L 3G1 Canada
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Colloidal silver diphosphide (AgP 2) nanocrystals as low overpotential catalysts for CO 2 reduction to tunable syngas. Nat Commun 2019; 10:5724. [PMID: 31844056 PMCID: PMC6915715 DOI: 10.1038/s41467-019-13388-8] [Citation(s) in RCA: 29] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2019] [Accepted: 10/31/2019] [Indexed: 12/31/2022] Open
Abstract
Production of syngas with tunable CO/H2 ratio from renewable resources is an ideal way to provide a carbon-neutral feedstock for liquid fuel production. Ag is a benchmark electrocatalysts for CO2-to-CO conversion but high overpotential limits the efficiency. We synthesize AgP2 nanocrystals (NCs) with a greater than 3-fold reduction in overpotential for electrochemical CO2-to-CO reduction compared to Ag and greatly enhanced stability. Density functional theory calculations reveal a significant energy barrier decrease in the formate intermediate formation step. In situ X-ray absorption spectroscopy (XAS) shows that a maximum Faradaic efficiency is achieved at an average silver valence state of +1.08 in AgP2 NCs. A photocathode consisting of a n+p-Si wafer coated with ultrathin Al2O3 and AgP2 NCs achieves an onset potential of 0.2 V vs. RHE for CO production and a partial photocurrent density for CO at −0.11 V vs. RHE (j−0.11, CO) of −3.2 mA cm−2. Conversion of CO2 into value-added chemicals by use of renewable energy is promising to achieve a carbon-neutral energy cycle. Here, the authors show that AgP2 is a stable, selective and efficient syngas catalyst for solar-to-fuel conversion with a 3-fold lower overpotential compared to the benchmark Ag catalyst.
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Lee SA, Lee TH, Kim C, Choi MJ, Park H, Choi S, Lee J, Oh J, Kim SY, Jang HW. Amorphous Cobalt Oxide Nanowalls as Catalyst and Protection Layers on n-Type Silicon for Efficient Photoelectrochemical Water Oxidation. ACS Catal 2019. [DOI: 10.1021/acscatal.9b03899] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Sol A. Lee
- Department of Materials Science and Engineering, Research Institute of Advanced Materials, Seoul National University, Seoul 08826, Republic of Korea
| | - Tae Hyung Lee
- Department of Materials Science and Engineering, Research Institute of Advanced Materials, Seoul National University, Seoul 08826, Republic of Korea
| | - Changyeon Kim
- Department of Materials Science and Engineering, Research Institute of Advanced Materials, Seoul National University, Seoul 08826, Republic of Korea
| | - Min-Ju Choi
- Department of Materials Science and Engineering, Research Institute of Advanced Materials, Seoul National University, Seoul 08826, Republic of Korea
| | - Hoonkee Park
- Department of Materials Science and Engineering, Research Institute of Advanced Materials, Seoul National University, Seoul 08826, Republic of Korea
| | - Seokhoon Choi
- Department of Materials Science and Engineering, Research Institute of Advanced Materials, Seoul National University, Seoul 08826, Republic of Korea
| | - Jinwoo Lee
- Department of Chemical and Biomolecular Engineering, Korea Advanced Institute of Science and Technology, Daejeon 34141, Republic of Korea
| | - Jihun Oh
- Graduate School of Energy, Environment, Water and Sustainability, Department of Materials Science and Engineering, Korea Advanced Institute of Science and Technology, Daejeon 34141, Republic of Korea
| | - Soo Young Kim
- Department of Materials Science and Engineering, Korea University, Seoul 02841, Republic of Korea
| | - Ho Won Jang
- Department of Materials Science and Engineering, Research Institute of Advanced Materials, Seoul National University, Seoul 08826, Republic of Korea
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Beranek R. Selectivity of Chemical Conversions: Do Light‐Driven Photoelectrocatalytic Processes Hold Special Promise? Angew Chem Int Ed Engl 2019. [DOI: 10.1002/ange.201908654] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Affiliation(s)
- Radim Beranek
- Institute of ElectrochemistryUlm University Albert-Einstein-Allee 47 89081 Ulm Germany
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50
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Beranek R. Selectivity of Chemical Conversions: Do Light‐Driven Photoelectrocatalytic Processes Hold Special Promise? Angew Chem Int Ed Engl 2019; 58:16724-16729. [DOI: 10.1002/anie.201908654] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2019] [Revised: 09/07/2019] [Indexed: 12/16/2022]
Affiliation(s)
- Radim Beranek
- Institute of ElectrochemistryUlm University Albert-Einstein-Allee 47 89081 Ulm Germany
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