201
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Li F, Li J, Zhang J, Gao L, Long X, Hu Y, Li S, Jin J, Ma J. NiO Nanoparticles Anchored on Phosphorus-Doped α-Fe 2 O 3 Nanoarrays: An Efficient Hole Extraction p-n Heterojunction Photoanode for Water Oxidation. CHEMSUSCHEM 2018; 11:2156-2164. [PMID: 29768719 DOI: 10.1002/cssc.201800571] [Citation(s) in RCA: 26] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/16/2018] [Revised: 05/14/2018] [Indexed: 06/08/2023]
Abstract
The photoelectrochemical (PEC) water-splitting efficiency of a hematite-based photoanode is still far from the theoretical value due to its poor surface reaction kinetics and high density of surface trapping states. To solve these drawbacks, a photoanode consisting of NiO nanoparticles anchored on a gradient phosphorus-doped α-Fe2 O3 nanorod (NR) array (NiO/P-α-Fe2 O3 ) was fabricated to achieve optimal light absorption and charge separation, as well as rapid surface reaction kinetics. Specifically, a photoanode with the NR array structure allowed a high mass-transport rate to be achieved, while phosphorus doping effectively decreased the number of surface trapping sites and improved the electrical conductivity of α-Fe2 O3 . Furthermore, the p-n junction that forms between NiO and P-α-Fe2 O3 can further improve the PEC performance due to efficient hole extraction and the water oxidization catalytic activity of NiO. Consequently, the NiO/P-α-Fe2 O3 NR photoanode produced a high photocurrent density of 2.08 mA cm-2 at 1.23 V versus a reversible hydrogen electrode and a 110 mV cathodic shift of the onset potential. This rational design of structure offers a new perspective in exploring high-performance PEC photoanodes.
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Affiliation(s)
- Feng Li
- State Key Laboratory of Applied Organic Chemistry (SKLAOC), The Key Laboratory of Catalytic Engineering of Gansu Province, College of Chemistry and Chemical Engineering, Lanzhou University, Lanzhou, Gansu, 730000, PR China
| | - Jing Li
- State Key Laboratory of Applied Organic Chemistry (SKLAOC), The Key Laboratory of Catalytic Engineering of Gansu Province, College of Chemistry and Chemical Engineering, Lanzhou University, Lanzhou, Gansu, 730000, PR China
| | - Jie Zhang
- School of Chemistry and ARC Centre of Excellence, for Electromaterials Science, Monash University, Clayton, VIC, 3800, Australia
| | - Lili Gao
- State Key Laboratory of Applied Organic Chemistry (SKLAOC), The Key Laboratory of Catalytic Engineering of Gansu Province, College of Chemistry and Chemical Engineering, Lanzhou University, Lanzhou, Gansu, 730000, PR China
| | - Xuefeng Long
- State Key Laboratory of Applied Organic Chemistry (SKLAOC), The Key Laboratory of Catalytic Engineering of Gansu Province, College of Chemistry and Chemical Engineering, Lanzhou University, Lanzhou, Gansu, 730000, PR China
| | - Yiping Hu
- State Key Laboratory of Applied Organic Chemistry (SKLAOC), The Key Laboratory of Catalytic Engineering of Gansu Province, College of Chemistry and Chemical Engineering, Lanzhou University, Lanzhou, Gansu, 730000, PR China
| | - Shuwen Li
- State Key Laboratory of Applied Organic Chemistry (SKLAOC), The Key Laboratory of Catalytic Engineering of Gansu Province, College of Chemistry and Chemical Engineering, Lanzhou University, Lanzhou, Gansu, 730000, PR China
| | - Jun Jin
- State Key Laboratory of Applied Organic Chemistry (SKLAOC), The Key Laboratory of Catalytic Engineering of Gansu Province, College of Chemistry and Chemical Engineering, Lanzhou University, Lanzhou, Gansu, 730000, PR China
| | - Jiantai Ma
- State Key Laboratory of Applied Organic Chemistry (SKLAOC), The Key Laboratory of Catalytic Engineering of Gansu Province, College of Chemistry and Chemical Engineering, Lanzhou University, Lanzhou, Gansu, 730000, PR China
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202
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Cheng KW, Hong SW. Influences of Silver and Zinc Contents in the Stannite Ag 2ZnSnS 4 Photoelectrodes on Their Photoelectrochemical Performances in the Saltwater Solution. ACS APPLIED MATERIALS & INTERFACES 2018; 10:22130-22142. [PMID: 29897232 DOI: 10.1021/acsami.8b04849] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
Multicomponent metal sulfide (stannite Ag2ZnSnS4) samples were grown onto the conductive metal oxide-coated glass substrates by using the sulfurization of cosputtering silver-zinc-tin precursors. Several [Ag]/[Zn + Sn] and [Zn]/[Sn] ratios were set in the metal precursors to investigate their influences on the crystal phases, microstructures, and physical properties of the stannite Ag2ZnSnS4 samples. The results of the crystal phases and the compositions of the samples showed that the stannite Ag2ZnSnS4 phase can be obtained using the two-step sulfurization process, which maintained the silver-zinc-tin precursors at 160 °C for 1 h and then kept them at 450 °C for 30 min under a sulfur/nitrogen atmosphere. N-type stannite Ag2ZnSnS4 samples with the carrier concentrations of 5.54 × 1012 to 9.11 × 1012 cm-3 can be obtained. High resistivities of Ag2ZnSnS4 samples were observed because of the low values of carrier concentration. Increasing the silver content in the sample can improve its photoelectrochemical (PEC) performance because of the decrease in the sample resistivity. The ratio of [Ag]/[Zn + Sn] at 0.8 and the ratio of [Zn]/[Sn] set at 0.90 in the stannite Ag2ZnSnS4 sample had the highest PEC performance of 0.31 mA·cm-2, with the potential set at 1.23 V versus the relative hydrogen electrode applied on the sample because of it having the lowest charge-transfer resistance in the electrolyte.
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Affiliation(s)
- Kong-Wei Cheng
- Department of Chemical and Materials Engineering , Chang Gung University , Taoyuan 333 , Taiwan
- Department of Orthopaedic Surgery , Chang Gung Memorial Hospital , Keelung Branch, Taoyuan 204 , Taiwan
| | - Shu-Wei Hong
- Department of Chemical and Materials Engineering , Chang Gung University , Taoyuan 333 , Taiwan
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203
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Li C, Luo Z, Wang T, Gong J. Surface, Bulk, and Interface: Rational Design of Hematite Architecture toward Efficient Photo-Electrochemical Water Splitting. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2018; 30:e1707502. [PMID: 29750372 DOI: 10.1002/adma.201707502] [Citation(s) in RCA: 75] [Impact Index Per Article: 12.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/22/2017] [Revised: 01/27/2018] [Indexed: 06/08/2023]
Abstract
Collecting and storing solar energy to hydrogen fuel through a photo-electrochemical (PEC) cell provides a clean and renewable pathway for future energy demands. Having earth-abundance, low biotoxicity, robustness, and an ideal n-type band position, hematite (α-Fe2 O3 ), the most common natural form of iron oxide, has occupied the research hotspot for decades. Here, a close look into recent progress of hematite photoanodes for PEC water splitting is provided. Effective approaches are introduced, such as cocatalysts loading and surface passivation layer deposition, to improve the hematite surface reaction in thermodynamics and kinetics. Second, typical methods for enhancing light absorption and accelerating charge transport in hematite bulk are reviewed, concentrating upon doping and nanostructuring. Third, the back contact between hematite and substrate, which affects interface states and electron transfer, is deliberated. In addition, perspectives on the key challenges and future prospects for the development of hematite photoelectrodes for PEC water splitting are given.
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Affiliation(s)
- Chengcheng Li
- Collaborative Innovation Center of Chemical Science and Engineering (Tianjin), Tianjin, 300072, China
- Key Laboratory for Green Chemical Technology of Ministry of Education, School of Chemical Engineering and Technology, Tianjin University, Tianjin, 300072, China
| | - Zhibin Luo
- Collaborative Innovation Center of Chemical Science and Engineering (Tianjin), Tianjin, 300072, China
- Key Laboratory for Green Chemical Technology of Ministry of Education, School of Chemical Engineering and Technology, Tianjin University, Tianjin, 300072, China
| | - Tuo Wang
- Collaborative Innovation Center of Chemical Science and Engineering (Tianjin), Tianjin, 300072, China
- Key Laboratory for Green Chemical Technology of Ministry of Education, School of Chemical Engineering and Technology, Tianjin University, Tianjin, 300072, China
| | - Jinlong Gong
- Collaborative Innovation Center of Chemical Science and Engineering (Tianjin), Tianjin, 300072, China
- Key Laboratory for Green Chemical Technology of Ministry of Education, School of Chemical Engineering and Technology, Tianjin University, Tianjin, 300072, China
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204
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Balu S, Uma K, Pan GT, Yang TCK, Ramaraj SK. Degradation of Methylene Blue Dye in the Presence of Visible Light Using SiO₂@α-Fe₂O₃ Nanocomposites Deposited on SnS₂ Flowers. MATERIALS 2018; 11:ma11061030. [PMID: 29914208 PMCID: PMC6025432 DOI: 10.3390/ma11061030] [Citation(s) in RCA: 84] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/03/2018] [Revised: 06/04/2018] [Accepted: 06/13/2018] [Indexed: 11/16/2022]
Abstract
Semiconductor materials have been shown to have good photocatalytic behavior and can be utilized for the photodegradation of organic pollutants. In this work, three-dimensional flower-like SnS2 (tin sulfide) was synthesized by a facile hydrothermal method. Core-shell structured SiO2@α-Fe2O3 nanocomposites were then deposited on the top of the SnS2 flowers. The as-synthesized nanocomposites were characterized by X-ray diffraction (XRD), Raman spectroscopy, field emission scanning electron microscopy (FE-SEM), transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS), UV–Vis Spectroscopy, Brunauer–Emmett–Teller (BET) surface area analysis, and photoluminescence (PL) spectroscopy. The photocatalytic behavior of the SnS2-SiO2@α-Fe2O3 nanocomposites was investigated by observing the degradation of methylene blue (MB). The results show an effective enhancement of photocatalytic activity for the degradation of MB especially for the 15 wt % SiO2@α-Fe2O3 nanocomposites on SnS2 flowers.
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Affiliation(s)
- Sridharan Balu
- Department of Chemical Engineering and biotechnology, National Taipei University of Technology, Taipei 106, Taiwan, (S.B.).
| | - Kasimayan Uma
- Precision Analysis and Research Center, National Taipei University of Technology, Taipei 106, Taiwan.
| | - Guan-Ting Pan
- Department of Chemical Engineering and biotechnology, National Taipei University of Technology, Taipei 106, Taiwan, (S.B.).
| | - Thomas C-K Yang
- Department of Chemical Engineering and biotechnology, National Taipei University of Technology, Taipei 106, Taiwan, (S.B.).
- Precision Analysis and Research Center, National Taipei University of Technology, Taipei 106, Taiwan.
| | - Sayee Kannan Ramaraj
- PG & Research Department of Chemistry, Thiagarajar College, Madurai 625009, Tamilnadu, India.
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205
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Cheng KW. Stable photoelectrochemical salt-water splitting using the n-ZnSe/n-Ag 8 SnS 6 photoanodes with the nanoscale surface state capacitances. J Taiwan Inst Chem Eng 2018. [DOI: 10.1016/j.jtice.2018.03.034] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/17/2022]
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206
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Zhu Y, Qian Q, Fan G, Zhu Z, Wang X, Li Z, Zou Z. Insight into the influence of high temperature annealing on the onset potential of Ti-doped hematite photoanodes for solar water splitting. CHINESE CHEM LETT 2018. [DOI: 10.1016/j.cclet.2018.01.022] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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207
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Suzuki TM, Nonaka T, Kitazumi K, Takahashi N, Kosaka S, Matsuoka Y, Sekizawa K, Suda A, Morikawa T. Highly Enhanced Electrochemical Water Oxidation Reaction over Hyperfine β-FeOOH(Cl):Ni Nanorod Electrode by Modification with Amorphous Ni(OH)2. BULLETIN OF THE CHEMICAL SOCIETY OF JAPAN 2018. [DOI: 10.1246/bcsj.20170426] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Affiliation(s)
- Tomiko M. Suzuki
- Toyota Central R&D Labs., Inc., 41-1 Yokomichi, Nagakute, Aichi 480-1192, Japan
| | - Takamasa Nonaka
- Toyota Central R&D Labs., Inc., 41-1 Yokomichi, Nagakute, Aichi 480-1192, Japan
| | - Kosuke Kitazumi
- Toyota Central R&D Labs., Inc., 41-1 Yokomichi, Nagakute, Aichi 480-1192, Japan
| | - Naoko Takahashi
- Toyota Central R&D Labs., Inc., 41-1 Yokomichi, Nagakute, Aichi 480-1192, Japan
| | - Satoru Kosaka
- Toyota Central R&D Labs., Inc., 41-1 Yokomichi, Nagakute, Aichi 480-1192, Japan
| | - Yoriko Matsuoka
- Toyota Central R&D Labs., Inc., 41-1 Yokomichi, Nagakute, Aichi 480-1192, Japan
| | - Keita Sekizawa
- Toyota Central R&D Labs., Inc., 41-1 Yokomichi, Nagakute, Aichi 480-1192, Japan
| | - Akihiko Suda
- Toyota Central R&D Labs., Inc., 41-1 Yokomichi, Nagakute, Aichi 480-1192, Japan
| | - Takeshi Morikawa
- Toyota Central R&D Labs., Inc., 41-1 Yokomichi, Nagakute, Aichi 480-1192, Japan
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208
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Gayathri P, Sajitha S, Vijitha I, Shaiju S, Remya R, Deb B. Tuning of physical and electrochemical properties of nanocrystalline tungsten oxide through ultraviolet photoactivation. Electrochim Acta 2018. [DOI: 10.1016/j.electacta.2018.04.028] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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209
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Liu Y, Wygant BR, Mabayoje O, Lin J, Kawashima K, Kim JH, Li W, Li J, Mullins CB. Interface Engineering and its Effect on WO 3-Based Photoanode and Tandem Cell. ACS APPLIED MATERIALS & INTERFACES 2018; 10:12639-12650. [PMID: 29608854 DOI: 10.1021/acsami.8b00304] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
During photoelectrochemical (PEC) water splitting, the reactions occur on the surface of the photoelectrode. Therefore, the properties of the interfaces between the various components of the electrode (semiconductor/semiconductor, semiconductor/catalyst, or photoelectrode/electrolyte) affect the PEC performance of the composite material. Notably, surface trap states may hinder charge transfer and transport properties, and also cause Fermi pinning, affecting the quasi-Fermi level and onset potential under illumination, which may in turn influence the PEC performance of the corresponding tandem cells. In this study, plate-like WO3 array films prepared by an aqueous chemical growth method were employed to highlight the effect of interfacial properties on the performance of a WO3-based photoanode. The Mott-Schottky and linear sweep voltammetry experiments prove the existence of surface trap states and Fermi pinning for pristine WO3, which are alleviated after an "etching" treatment and disappeared after surface passivation by a Ga2O3 layer. Both etching and passivation increase the oxygen evolution activity and the Faradaic efficiency for the oxygen evolution reaction (OER). After loading a permeable catalyst (FeOOH), the photocurrent is further increased, and there is a synergistic effect between loading of the electrocatalyst with etching or passivation. The onset potentials of the samples follow the trends: etch-WO3/FeOOH < WO3/FeOOH ≤ WO3/Ga2O3/FeOOH < etch-WO3 < WO3 < WO3/Ga2O3, indicating that the interfacial properties have a significant effect on the PEC performance. Meanwhile, the modified WO3-based electrode was combined with a dye-sensitized solar cell to fabricate tandem cell, which showed 2.42-fold photocurrent density compared with the pristine WO3-based tandem cell.
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Affiliation(s)
- Yang Liu
- College of Chemistry and Chemical Engineering , Central South University , Changsha 410083 , China
- Department of Chemical Engineering and Department of Chemistry , University of Texas at Austin , Austin , Texas 78712-0231 , United States
| | - Bryan R Wygant
- Department of Chemical Engineering and Department of Chemistry , University of Texas at Austin , Austin , Texas 78712-0231 , United States
| | - Oluwaniyi Mabayoje
- Department of Chemical Engineering and Department of Chemistry , University of Texas at Austin , Austin , Texas 78712-0231 , United States
| | - Jie Lin
- Department of Chemical Engineering and Department of Chemistry , University of Texas at Austin , Austin , Texas 78712-0231 , United States
- Pen-Tung Sah Micro-Nano Science and Technology Institute , Xiamen University , Xiamen , Fujian 361005 , China
| | - Kenta Kawashima
- Department of Chemical Engineering and Department of Chemistry , University of Texas at Austin , Austin , Texas 78712-0231 , United States
| | - Jun-Hyuk Kim
- Department of Chemical Engineering and Department of Chemistry , University of Texas at Austin , Austin , Texas 78712-0231 , United States
| | - Wenzhang Li
- College of Chemistry and Chemical Engineering , Central South University , Changsha 410083 , China
| | - Jie Li
- College of Chemistry and Chemical Engineering , Central South University , Changsha 410083 , China
| | - C Buddie Mullins
- Department of Chemical Engineering and Department of Chemistry , University of Texas at Austin , Austin , Texas 78712-0231 , United States
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210
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Esarey SL, Bartlett BM. pH-Dependence of Binding Constants and Desorption Rates of Phosphonate- and Hydroxamate-Anchored [Ru(bpy) 3] 2+ on TiO 2 and WO 3. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2018; 34:4535-4547. [PMID: 29601204 DOI: 10.1021/acs.langmuir.8b00263] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
The binding constants and rate constants for desorption of the modified molecular dye [Ru(bpy)3]2+ anchored by either phosphonate or hydroxamate on the bipyridine ligand to anatase TiO2 and WO3 have been measured. In aqueous media at pH 1-10, repulsive electrostatic interactions between the negatively charged anchor and the negatively charged surface govern phosphonate desorption under neutral and basic conditions for TiO2 anatase due to the high acidity of phosphonic acid (p Ka,4 = 5.1). In contrast, the lower acidity of hydroxamate (p Ka,1 = 6.5, p Ka,2 = 9.1) leads to little change in adsorption/desorption properties as a function of pH from 1 to 7. The binding constant for hydroxamate is 103 in water, independent of pH in this range. These results are true for WO3 as well, but are not reported at pH > 4 due to its Arrhenius acidity. Kinetics for desorption as a function of pH are reported, with a proposed mechanism for phosphonate desorption at high pH being the electrostatic repulsion of negative charges between the surface and the anionic anchor. Further, the hydroxamic acid anchor itself is likely the site of quasi-reversible redox activity in [Ru(bpy)2(2,2'-bpy-4,4'-(C(O)N(OH))2)]2+, which does not lead to any measurable deterioration of the complex within 2 h of dark cyclic voltammogram scans in aqueous media. These results posit phosphonate as the preferred anchoring group under acidic conditions and hydroxamate for neutral/basic conditions.
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Affiliation(s)
- Samuel L Esarey
- Department of Chemistry , University of Michigan , 930 North University Avenue , Ann Arbor , Michigan 48109 , United States
| | - Bart M Bartlett
- Department of Chemistry , University of Michigan , 930 North University Avenue , Ann Arbor , Michigan 48109 , United States
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211
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Jiang CM, Segev G, Hess LH, Liu G, Zaborski G, Toma FM, Cooper JK, Sharp ID. Composition-Dependent Functionality of Copper Vanadate Photoanodes. ACS APPLIED MATERIALS & INTERFACES 2018; 10:10627-10633. [PMID: 29489326 DOI: 10.1021/acsami.8b02977] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
To understand functional roles of constituent elements in ternary metal oxide photoanodes, essential photoelectrochemical (PEC) properties are systematically analyzed on a series of copper vanadate compounds with different Cu:V elemental ratios. Homogeneous and highly continuous thin films of β-Cu2V2O7, γ-Cu3V2O8, Cu11V6O26, and Cu5V2O10 are grown via reactive co-sputtering and their performance characteristics for the light-driven oxygen evolution reaction are evaluated. All four compounds have similar bandgaps in the range of 1.83-2.03 eV, though Cu-rich phases exhibit stronger optical absorption and higher charge separation efficiencies. Transient photocurrent analysis reveals a reduction of surface catalytic activity with increasing Cu:V elemental ratio due to competitive charge recombination at Cu-related surface states. This comprehensive analysis of PEC functionalities-including photon absorption, carrier separation, and heterogeneous charge transfer-informs strategies for improving PEC activity in the copper vanadate materials system and provides insights that may aid discovery, design, and engineering of new photoelectrode materials.
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Affiliation(s)
| | | | | | | | | | | | | | - Ian D Sharp
- Walter Schottky Institut and Physik Department , Technische Universität München , Am Coulombwall 4 , 85748 Garching , Germany
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212
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Cheng KW, Chou Y. Photoelectrochemical performances of the cubic AgSnSe2 thin film electrodes created using the selenization of thermal evaporated Ag-Sn metal precursors. J Taiwan Inst Chem Eng 2018. [DOI: 10.1016/j.jtice.2017.11.029] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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213
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Klotz D, Grave DA, Dotan H, Rothschild A. Empirical Analysis of the Photoelectrochemical Impedance Response of Hematite Photoanodes for Water Photo-oxidation. J Phys Chem Lett 2018; 9:1466-1472. [PMID: 29512388 DOI: 10.1021/acs.jpclett.8b00096] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
Photoelectrochemical impedance spectroscopy (PEIS) is a useful tool for the characterization of photoelectrodes for solar water splitting. However, the analysis of PEIS spectra often involves a priori assumptions that might bias the results. This work puts forward an empirical method that analyzes the distribution of relaxation times (DRT), obtained directly from the measured PEIS spectra of a model hematite photoanode. By following how the DRT evolves as a function of control parameters such as the applied potential and composition of the electrolyte solution, we obtain unbiased insights into the underlying mechanisms that shape the photocurrent. In a subsequent step, we fit the data to a process-oriented equivalent circuit model (ECM) whose makeup is derived from the DRT analysis in the first step. This yields consistent quantitative trends of the dominant polarization processes observed. Our observations reveal a common step for the photo-oxidation reactions of water and H2O2 in alkaline solution.
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Affiliation(s)
- Dino Klotz
- Department of Materials Science and Engineering , Technion - Israel Institute of Technology , Haifa 32000 , Israel
- International Institute for Carbon-Neutral Energy Research , Kyushu University , 744 Motooka , Nishi-ku Fukuoka 819-0395 , Japan
| | - Daniel A Grave
- Department of Materials Science and Engineering , Technion - Israel Institute of Technology , Haifa 32000 , Israel
| | - Hen Dotan
- Department of Materials Science and Engineering , Technion - Israel Institute of Technology , Haifa 32000 , Israel
| | - Avner Rothschild
- Department of Materials Science and Engineering , Technion - Israel Institute of Technology , Haifa 32000 , Israel
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214
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Shi Q, Murcia-López S, Tang P, Flox C, Morante JR, Bian Z, Wang H, Andreu T. Role of Tungsten Doping on the Surface States in BiVO4 Photoanodes for Water Oxidation: Tuning the Electron Trapping Process. ACS Catal 2018. [DOI: 10.1021/acscatal.7b04277] [Citation(s) in RCA: 100] [Impact Index Per Article: 16.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Qin Shi
- College of Environmental Science and Engineering, Beijing Forestry University, Beijing 100083, PR China
- Department of Advanced Materials for Energy, Catalonia Institute for Energy Research (IREC), Catalonia, Spain
| | - Sebastián Murcia-López
- Department of Advanced Materials for Energy, Catalonia Institute for Energy Research (IREC), Catalonia, Spain
| | - Pengyi Tang
- Department of Advanced Materials for Energy, Catalonia Institute for Energy Research (IREC), Catalonia, Spain
- Catalan Institute of Nanoscience and Nanotechnology (ICN2), CSIC and The Barcelona Institute of Science and Technology (BIST), Campus UAB, Bellaterra, 08193 Barcelona, Spain
| | - Cristina Flox
- Department of Advanced Materials for Energy, Catalonia Institute for Energy Research (IREC), Catalonia, Spain
| | - Joan R. Morante
- Department of Advanced Materials for Energy, Catalonia Institute for Energy Research (IREC), Catalonia, Spain
- University of Barcelona (UB), Marti i Franquès 1, 08028 Barcelona, Catalonia, Spain
| | - Zhaoyong Bian
- College of Water Sciences, Beijing Normal University, Beijing 100875, PR China
| | - Hui Wang
- College of Environmental Science and Engineering, Beijing Forestry University, Beijing 100083, PR China
| | - Teresa Andreu
- Department of Advanced Materials for Energy, Catalonia Institute for Energy Research (IREC), Catalonia, Spain
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215
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Kim JK, Cho Y, Jeong MJ, Levy-Wendt B, Shin D, Yi Y, Wang DH, Zheng X, Park JH. Rapid Formation of a Disordered Layer on Monoclinic BiVO 4 : Co-Catalyst-Free Photoelectrochemical Solar Water Splitting. CHEMSUSCHEM 2018; 11:933-940. [PMID: 29274301 DOI: 10.1002/cssc.201702173] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/15/2017] [Revised: 12/20/2017] [Indexed: 05/08/2023]
Abstract
A surface disordered layer is a plausible approach to improve the photoelectrochemical performance of TiO2 . However, the formation of a crystalline disordered layer in BiVO4 and its effectiveness towards photoelectrochemical water splitting has remained a big challenge. Here, we report a rapid solution process (within 5 s) that is able to form a disordered layer of a few nanometers thick on the surface of BiVO4 nanoparticles using a specific solution with a controllable reducing power. The disordered layer on BiVO4 alleviates charge recombination at the electrode-electrolyte interface and reduces the onset potential greatly, which in turn results in a photocurrent density of approximately 2.3 mA cm-2 at 1.23 V versus the reversible hydrogen electrode (RHE). This value is 2.1 times higher than that of bare BiVO4 . The enhanced photoactivity is attributed to the increased charge separation and transfer efficiencies, which resolve the intrinsic drawbacks of bare BiVO4 such as the short hole diffusion length of around 100 nm and poor surface oxygen evolution reactivity.
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Affiliation(s)
- Jung Kyu Kim
- School of Chemical Engineering, Sungkyunkwan University, 2066 Seobu-ro, Jangan-gu, Suwon, 16419, Republic of Korea
- Department of Chemical and Biomolecular Engineering, Yonsei University, 50 Yonsei-ro, Seodaemun-gu, Seoul, 03722, Republic of Korea
| | - Yoonjun Cho
- Department of Chemical and Biomolecular Engineering, Yonsei University, 50 Yonsei-ro, Seodaemun-gu, Seoul, 03722, Republic of Korea
| | - Myung Jin Jeong
- Department of Chemical and Biomolecular Engineering, Yonsei University, 50 Yonsei-ro, Seodaemun-gu, Seoul, 03722, Republic of Korea
| | - Ben Levy-Wendt
- Department of Mechanical Engineering, Stanford University, Stanford, CA, 94305, USA
| | - Dongguen Shin
- Institute of Physics and Applied Physics, Yonsei University, 50 Yonsei-ro, Seodaemun-gu, Seoul, 03722, Republic of Korea
| | - Yeonjin Yi
- Institute of Physics and Applied Physics, Yonsei University, 50 Yonsei-ro, Seodaemun-gu, Seoul, 03722, Republic of Korea
| | - Dong Hwan Wang
- School of Integrative Engineering, Chung-Ang University, 84 Heukseok-ro, Dongjak-gu, Seoul, 156-756, Republic of Korea
| | - Xiaolin Zheng
- Department of Mechanical Engineering, Stanford University, Stanford, CA, 94305, USA
| | - Jong Hyeok Park
- Department of Chemical and Biomolecular Engineering, Yonsei University, 50 Yonsei-ro, Seodaemun-gu, Seoul, 03722, Republic of Korea
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216
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Gao Y, Hamann TW. Quantitative hole collection for photoelectrochemical water oxidation with CuWO 4. Chem Commun (Camb) 2018; 53:1285-1288. [PMID: 28067348 DOI: 10.1039/c6cc09029j] [Citation(s) in RCA: 42] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
The hole collection efficiency of water oxidation was evaluated for CuWO4 electrodes from comparisons of the photocurrent of H2O2 and Na2SO3 oxidation as well as intensity modulated photocurrent spectroscopy (IMPS) measurements. We found current multiplication using H2O2, however use of Na2SO3 and IMPS revealed quantitative water oxidation at 1.23 V vs. RHE.
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Affiliation(s)
- Yuan Gao
- Department of Chemistry, Michigan State University, 578 S Shaw Lane, East Lansing, MI 48824, USA.
| | - Thomas W Hamann
- Department of Chemistry, Michigan State University, 578 S Shaw Lane, East Lansing, MI 48824, USA.
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217
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Qiu P, Yang H, Yang L, Wang Q, Ge L. Solar water splitting with nanostructured hematite: The role of annealing-temperature. Electrochim Acta 2018. [DOI: 10.1016/j.electacta.2018.02.030] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
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218
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Liu A, Zhang Y, Ma W, Song W, Chen C, Zhao J. Facial boron incorporation in hematite photoanode for enhanced photoelectrochemical water oxidation. J Photochem Photobiol A Chem 2018. [DOI: 10.1016/j.jphotochem.2017.08.045] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
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219
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Tang F, Cheng W, Su H, Zhao X, Liu Q. Smoothing Surface Trapping States in 3D Coral-Like CoOOH-Wrapped-BiVO 4 for Efficient Photoelectrochemical Water Oxidation. ACS APPLIED MATERIALS & INTERFACES 2018; 10:6228-6234. [PMID: 29384358 DOI: 10.1021/acsami.7b15674] [Citation(s) in RCA: 41] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
Highly efficient oxygen evolution driven by abundant sunlight is a key to realize overall water splitting for large-scale conversion of renewable energy. Here, we report a strategy for the interfacial atomic and electronic coupling of layered CoOOH and BiVO4 to deactivate the surface trapping states and suppress the charge-carrier recombination for high photoelectrochemical (PEC) water oxidation activity. The successful synthesis of a 3D ultrathin-CoOOH-overlayer-coated coral-like BiVO4 photoanode effectively tailors the migration route of photocarriers on the semiconductor/liquid interface to realize a great increase of ∼200% in the photovoltage relative to bare BiVO4, consequently decreasing the corresponding onset potential of PEC water splitting from 0.60 to 0.20 VRHE. As a result, the unique CoOOH/BiVO4 photoanode could efficiently perform PEC water oxidation in a neutral aqueous solution (pH = 7) with a high photocurrent density of 4.0 mA/cm2 at 1.23 VRHE and a prominent quantum efficiency of 65% at 450 nm. Electronic structural characterizations and theoretical calculations reveal that the combination of layered CoOOH and BiVO4 forming interfacial oxo-bridge bonding could greatly eliminate surface trapping states and promote the direct transfer of photogenerated holes from the valence band to the surface water redox potential for water oxidation.
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Affiliation(s)
- Fumin Tang
- National Synchrotron Radiation Laboratory, University of Science and Technology of China , Hefei 230029, Anhui, P. R. China
| | - Weiren Cheng
- National Synchrotron Radiation Laboratory, University of Science and Technology of China , Hefei 230029, Anhui, P. R. China
| | - Hui Su
- National Synchrotron Radiation Laboratory, University of Science and Technology of China , Hefei 230029, Anhui, P. R. China
| | - Xu Zhao
- National Synchrotron Radiation Laboratory, University of Science and Technology of China , Hefei 230029, Anhui, P. R. China
| | - Qinghua Liu
- National Synchrotron Radiation Laboratory, University of Science and Technology of China , Hefei 230029, Anhui, P. R. China
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220
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Zhang Y, Zhang H, Liu A, Chen C, Song W, Zhao J. Rate-Limiting O–O Bond Formation Pathways for Water Oxidation on Hematite Photoanode. J Am Chem Soc 2018; 140:3264-3269. [DOI: 10.1021/jacs.7b10979] [Citation(s) in RCA: 98] [Impact Index Per Article: 16.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Affiliation(s)
- Yuchao Zhang
- Key Laboratory of Photochemistry, CAS Research/Education Center for Excellence in Molecular Sciences, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190, P. R. China
- University of Chinese Academy of Sciences, Beijing 100049, P. R. China
| | - Hongna Zhang
- Key Laboratory of Photochemistry, CAS Research/Education Center for Excellence in Molecular Sciences, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190, P. R. China
- University of Chinese Academy of Sciences, Beijing 100049, P. R. China
| | - Anan Liu
- Key Laboratory of Photochemistry, CAS Research/Education Center for Excellence in Molecular Sciences, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190, P. R. China
- University of Chinese Academy of Sciences, Beijing 100049, P. R. China
| | - Chuncheng Chen
- Key Laboratory of Photochemistry, CAS Research/Education Center for Excellence in Molecular Sciences, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190, P. R. China
- University of Chinese Academy of Sciences, Beijing 100049, P. R. China
| | - Wenjing Song
- Key Laboratory of Photochemistry, CAS Research/Education Center for Excellence in Molecular Sciences, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190, P. R. China
- University of Chinese Academy of Sciences, Beijing 100049, P. R. China
| | - Jincai Zhao
- Key Laboratory of Photochemistry, CAS Research/Education Center for Excellence in Molecular Sciences, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190, P. R. China
- University of Chinese Academy of Sciences, Beijing 100049, P. R. China
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221
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Melo MA, Wu Z, Nail BA, De Denko AT, Nogueira AF, Osterloh FE. Surface Photovoltage Measurements on a Particle Tandem Photocatalyst for Overall Water Splitting. NANO LETTERS 2018; 18:805-810. [PMID: 29276832 DOI: 10.1021/acs.nanolett.7b04020] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
Surface photovoltage spectroscopy (SPS) is used to measure the photopotential across a Ru-SrTiO3:Rh/BiVO4 particle tandem overall water splitting photocatalyst. The tandem is synthesized from Ru-modified SrTiO3:Rh nanocrystals and BiVO4 microcrystals by electrostatic assembly followed by thermal annealing. It splits water into H2 and O2 with an apparent quantum efficiency of 1.29% at 435 nm and a solar to hydrogen conversion efficiency of 0.028%. According to SPS, a photovoltage develops above 2.20 eV, the effective band gap of the tandem, and reaches its maximal value of -2.45 V at 435 nm (2.44 mW cm-2), which corresponds to 96% of the theoretical limit of the photocatalyst film on the fluorine-doped tin-oxide-coated glass (FTO) substrate. Charge separation is 82% reversible with 18% of charge carriers being trapped in defect states. The unusually strong light intensity dependence of the photovoltage (1.16 V per decade) is attributed to depletion layer changes inside of the BiVO4 microcrystals. These findings promote the understanding of solar energy conversion with inorganic particle photocatalysts.
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Affiliation(s)
- Mauricio A Melo
- Department of Chemistry, University of California, Davis , One Shields Avenue, Davis, California 95616, United States
- Institute of Chemistry, University of Campinas, UNICAMP , P.O. Box 6154, Campinas, São Paulo 13084-971, Brazil
| | - Zongkai Wu
- Department of Chemistry, University of California, Davis , One Shields Avenue, Davis, California 95616, United States
| | - Benjamin A Nail
- Department of Chemistry, University of California, Davis , One Shields Avenue, Davis, California 95616, United States
| | - Alexandra T De Denko
- Department of Chemistry, University of California, Davis , One Shields Avenue, Davis, California 95616, United States
| | - Ana F Nogueira
- Institute of Chemistry, University of Campinas, UNICAMP , P.O. Box 6154, Campinas, São Paulo 13084-971, Brazil
| | - Frank E Osterloh
- Department of Chemistry, University of California, Davis , One Shields Avenue, Davis, California 95616, United States
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222
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Krumov MR, Simpson BH, Counihan MJ, Rodríguez-López J. In Situ Quantification of Surface Intermediates and Correlation to Discharge Products on Hematite Photoanodes Using a Combined Scanning Electrochemical Microscopy Approach. Anal Chem 2018; 90:3050-3057. [DOI: 10.1021/acs.analchem.7b04896] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
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223
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Du C, Wang J, Liu X, Yang J, Cao K, Wen Y, Chen R, Shan B. Ultrathin CoO x-modified hematite with low onset potential for solar water oxidation. Phys Chem Chem Phys 2018; 19:14178-14184. [PMID: 28530305 DOI: 10.1039/c7cp01588g] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Photoelectrochemical water splitting holds great potential for solar energy conversion and storage with zero greenhouse gas emission. Integration of a suitable co-catalyst with an absorber material enables the realization of highly efficient photocleavage of water. Herein, nanostructured hematite film was coated with an ultrathin and conformal CoOx overlayer through atomic layer deposition (ALD). The best performing hybrid hematite with a 2-3 nm ALD CoOx overlayer yielded a remarkable turn on potential of 0.6 VRHE for the water oxidation reaction. Moreover, material analyses revealed that the surface amorphous CoOx/Co(OH)2 component exhibited good optical transparency and hydrophilic properties, which were beneficial for the formation of an ideal hematite/electrolyte interface. In addition to the presence of the CoOx overlayer, a negative shift of flat band potential (VFB) as well as suppression of surface recombination helped to significantly promote the charge separation and collection properties, contributing to the overall solar conversion efficiency. As a result, the external quantum efficiency (IPCE) obtained on hematite increases by 66% at 1.23 VRHE.
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Affiliation(s)
- Chun Du
- State Key Laboratory of Materials Processing and Die & Mould Technology, School of Materials Science and Engineering, Huazhong University of Science and Technology, Wuhan 430074, Hubei, People's Republic of China.
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224
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Zhao X, Feng J, Chen S, Huang Y, Sum TC, Chen Z. New insight into the roles of oxygen vacancies in hematite for solar water splitting. Phys Chem Chem Phys 2018; 19:1074-1082. [PMID: 27858025 DOI: 10.1039/c6cp06410h] [Citation(s) in RCA: 59] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Oxygen vacancies play an important role in the performance improvement of oxide semiconductors as photoanodes for water splitting, such as TiO2, WO3, and Fe2O3. Conductivity improvement due to the presence of oxygen vacancies was reported to be the main reason for the enhanced performance. However, oxygen vacancies may also affect light absorption and charge transfer through the solid/electrolyte interface. The roles of oxygen vacancies have not been thoroughly discussed in the past. Herein, with hematite as an example, the effects of oxygen vacancies on bulk charge transport and surface catalysis are quantitatively analyzed by decoupling photon absorption, interfacial charge transfer and charge separation processes. Oxygen vacancies improve the charge separation of both pristine and Ti-doped hematite. However, opposite observations are found in the charge transfer process for pristine and Ti-doped hematite: the positive effect in pristine hematite but the negative effect in the Ti-doped one. An electrochemical technique is used to analyze the different influences on pristine and Ti-doped hematite to unravel the mechanism of the opposite observations caused by oxygen vacancies. The current study sheds lights on how oxygen vacancies affect various aspects of important factors behind PEC performance, which is helpful to the development of more efficient photoanodes in the future.
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Affiliation(s)
- Xin Zhao
- School of Materials Science and Engineering, Nanyang Technological University, 50 Nanyang Avenue, 639798, Singapore, Singapore.
| | - Jianyong Feng
- School of Materials Science and Engineering, Nanyang Technological University, 50 Nanyang Avenue, 639798, Singapore, Singapore.
| | - Shi Chen
- School of Physical and Mathematical Sciences, Nanyang Technological University, 637371, Singapore, Singapore
| | - Yizhong Huang
- School of Materials Science and Engineering, Nanyang Technological University, 50 Nanyang Avenue, 639798, Singapore, Singapore.
| | - Tze Chien Sum
- School of Physical and Mathematical Sciences, Nanyang Technological University, 637371, Singapore, Singapore
| | - Zhong Chen
- School of Materials Science and Engineering, Nanyang Technological University, 50 Nanyang Avenue, 639798, Singapore, Singapore.
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225
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Xu Z, Wang H, Wen Y, Li W, Sun C, He Y, Shi Z, Pei L, Chen Y, Yan S, Zou Z. Balancing Catalytic Activity and Interface Energetics of Electrocatalyst-Coated Photoanodes for Photoelectrochemical Water Splitting. ACS APPLIED MATERIALS & INTERFACES 2018; 10:3624-3633. [PMID: 29308871 DOI: 10.1021/acsami.7b17348] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
For photoelectrochemical (PEC) water splitting, the interface interactions among semiconductors, electrocatalysts, and electrolytes affect the charge separation and catalysis in turn. Here, through the changing of the bath temperature, Co-based oxygen evolution catalysts (OEC) with different crystallinities were electrochemically deposited on Ti-doped Fe2O3 (Ti-Fe2O3) photoanodes. We found: (1) the OEC with low crystallinity is highly ion-permeable, decreasing the interactions between OEC and photoanode due to the intimate interaction between semiconductor and electrolyte; (2) the OEC with high crystallinity is nearly ion-impermeable, is beneficial to form a constant buried junction with semiconductor, and exhibits the low OEC catalytic activity; and (3) the OEC with moderate crystallinity is partially electrolyte-screened, thus contributing to the formation of ideal band bending underneath surface of semiconductor for charge separation and the highly electrocatalytic activity of OEC for lowering over-potentials of water oxidation. Our results demonstrate that to balance the water oxidation activity of OEC and OEC-semiconductor interface energetics is crucial for highly efficient solar energy conversion; in particular, the energy transducer is a semiconductor with a shallow or moderate valence-band level.
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Affiliation(s)
| | | | - Yunzhou Wen
- State Key Laboratory of Molecular Engineering of Polymers, Department of Macromolecular Science, Laboratory of Advanced Materials, Fudan University , Shanghai 200438, PR China
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226
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Zhang P, Wang T, Gong J. Passivation of surface states by ALD-grown TiO2 overlayers on Ta3N5 anodes for photoelectrochemical water oxidation. Chem Commun (Camb) 2018; 52:8806-9. [PMID: 27292872 DOI: 10.1039/c6cc03411j] [Citation(s) in RCA: 37] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
This paper describes the fabrication of TiO2 overlayers by atomic layer deposition to passivate the surface states on Ta3N5 thin film anodes for photoelectrochemical water oxidation. The removal of surface states reduces the overpotential and decreases the density of surface recombination centers, resulting in enhanced activity through effective utilization of photogenerated charge carriers.
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Affiliation(s)
- Peng Zhang
- Key Laboratory for Green Chemical Technology of Ministry of Education, School of Chemical Engineering and Technology, Tianjin University; Collaborative Innovation Center of Chemical Science and Engineering, Tianjin 300072, China.
| | - Tuo Wang
- Key Laboratory for Green Chemical Technology of Ministry of Education, School of Chemical Engineering and Technology, Tianjin University; Collaborative Innovation Center of Chemical Science and Engineering, Tianjin 300072, China.
| | - Jinlong Gong
- Key Laboratory for Green Chemical Technology of Ministry of Education, School of Chemical Engineering and Technology, Tianjin University; Collaborative Innovation Center of Chemical Science and Engineering, Tianjin 300072, China.
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227
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Kraushofer F, Jakub Z, Bichler M, Hulva J, Drmota P, Weinold M, Schmid M, Setvin M, Diebold U, Blaha P, Parkinson GS. Atomic-Scale Structure of the Hematite α-Fe 2O 3(11̅02) "R-Cut" Surface. THE JOURNAL OF PHYSICAL CHEMISTRY. C, NANOMATERIALS AND INTERFACES 2018; 122:1657-1669. [PMID: 29492182 PMCID: PMC5823487 DOI: 10.1021/acs.jpcc.7b10515] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/24/2017] [Revised: 12/08/2017] [Indexed: 05/26/2023]
Abstract
The α-Fe2O3(11̅02) surface (also known as the hematite r-cut or (012) surface) was studied using low-energy electron diffraction (LEED), X-ray photoelectron spectroscopy (XPS), ultraviolet photoelectron spectroscopy (UPS), scanning tunneling microscopy (STM), noncontact atomic force microscopy (nc-AFM), and ab initio density functional theory (DFT)+U calculations. Two surface structures are stable under ultrahigh vacuum (UHV) conditions; a stoichiometric (1 × 1) surface can be prepared by annealing at 450 °C in ≈10-6 mbar O2, and a reduced (2 × 1) reconstruction is formed by UHV annealing at 540 °C. The (1 × 1) surface is close to an ideal bulk termination, and the undercoordinated surface Fe atoms reduce the surface bandgap by ≈0.2 eV with respect to the bulk. The work function is measured to be 5.7 ± 0.2 eV, and the VBM is located 1.5 ± 0.1 eV below EF. The images obtained from the (2 × 1) reconstruction cannot be reconciled with previously proposed models, and a new "alternating trench" structure is proposed based on an ordered removal of lattice oxygen atoms. DFT+U calculations show that this surface is favored in reducing conditions and that 4-fold-coordinated Fe2+ cations at the surface introduce gap states approximately 1 eV below EF. The work function on the (2 × 1) termination is 5.4 ± 0.2 eV.
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Affiliation(s)
- Florian Kraushofer
- Institute
of Applied Physics, Vienna University of
Technology, Vienna, Austria
| | - Zdenek Jakub
- Institute
of Applied Physics, Vienna University of
Technology, Vienna, Austria
| | - Magdalena Bichler
- Institute
of Materials Chemistry, Vienna University
of Technology, Vienna, Austria
| | - Jan Hulva
- Institute
of Applied Physics, Vienna University of
Technology, Vienna, Austria
| | - Peter Drmota
- Institute
of Applied Physics, Vienna University of
Technology, Vienna, Austria
| | - Michael Weinold
- Institute
of Applied Physics, Vienna University of
Technology, Vienna, Austria
| | - Michael Schmid
- Institute
of Applied Physics, Vienna University of
Technology, Vienna, Austria
| | - Martin Setvin
- Institute
of Applied Physics, Vienna University of
Technology, Vienna, Austria
| | - Ulrike Diebold
- Institute
of Applied Physics, Vienna University of
Technology, Vienna, Austria
| | - Peter Blaha
- Institute
of Materials Chemistry, Vienna University
of Technology, Vienna, Austria
| | - Gareth S. Parkinson
- Institute
of Applied Physics, Vienna University of
Technology, Vienna, Austria
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228
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Rajamohan S, Kumaravel V, Abdel-Wahab A, Ayyadurai S, Muthuramalingam R. Exploration of Ag decoration and Bi doping on the photocatalytic activity α-Fe2
O3
under simulated solar light irradiation. CAN J CHEM ENG 2018. [DOI: 10.1002/cjce.23122] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Affiliation(s)
- Satheesh Rajamohan
- Department of Chemistry; Sethu Institute of Technology; Madurai 626 115 Tamil Nadu India
| | - Vignesh Kumaravel
- Chemical Engineering Program; Texas A&M University at Qatar; Doha 23874 Qatar
| | - Ahmed Abdel-Wahab
- Chemical Engineering Program; Texas A&M University at Qatar; Doha 23874 Qatar
| | - Suganthi Ayyadurai
- Post Graduate & Research Department of Chemistry; Thiagarajar College; Madurai 625009 Tamil Nadu India
| | - Rajarajan Muthuramalingam
- Post Graduate & Research Department of Chemistry; Cardamom Planter's Association College; Bodinayakanur 626 513 Tamil Nadu India
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229
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Xu Z, Fan Z, Shi Z, Li M, Feng J, Pei L, Zhou C, Zhou J, Yang L, Li W, Xu G, Yan S, Zou Z. Interface Manipulation to Improve Plasmon-Coupled Photoelectrochemical Water Splitting on α-Fe 2 O 3 Photoanodes. CHEMSUSCHEM 2018; 11:237-244. [PMID: 28940828 DOI: 10.1002/cssc.201701679] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/04/2017] [Revised: 09/15/2017] [Indexed: 05/07/2023]
Abstract
The plasmon resonance effect of metal nanoparticles (NPs) offers a promising route to improve the solar energy conversion efficiency of semiconductors. In this study, it is revealed that hot electrons generated by the plasmon resonance effect of Au NPs tend to inject into the surface states instead of the conduction band of Fe2 O3 photoanodes, and then severe surface recombination occurs. Such an electron-transfer process seems to be independent of external applied potentials, but is sensitive to metal-semiconductor interface properties. Passivating the surface states of Fe2 O3 with a noncatalytic Al2 O3 layer can construct an effective resonant energy-transfer interface between Ti-doped Fe2 O3 (Ti-Fe2 O3 ) and Au NPs. In such a Ti-Fe2 O3 /Al2 O3 /Au electrode configuration, the enhanced photoelectrochemical (PEC) water-splitting performance can be attributed to the following two factors: 1) in the non-light-responsive wavelength range of Au NPs, both the relaxing Fermi pinning effect of the Al2 O3 passivation layer and the higher work function of Au enlarge band bending; thus promoting the charge separation; and 2) in the light-responsive wavelength range of Au NPs, the effective resonant energy transfer contributes to light harvesting and conversion. The interface manipulation proposed herein may provide a new route to design efficient plasmonic PEC devices for energy conversion.
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Affiliation(s)
- Zhe Xu
- National Laboratory of Solid State Microstructures, Collaborative Innovation Center of Advanced Microstructures, College of Engineering and Applied Sciences, Nanjing University, Nanjing, Jiangsu, 210093, PR China
| | - Zhongwen Fan
- National Laboratory of Solid State Microstructures, Collaborative Innovation Center of Advanced Microstructures, College of Engineering and Applied Sciences, Nanjing University, Nanjing, Jiangsu, 210093, PR China
| | - Zhan Shi
- Jiangsu Province Key Laboratory for Nanotechnology, Eco-Materials and Renewable Energy Research Center (ERERC), School of Physics, Nanjing University, Nanjing, Jiangsu, 210093, PR China
| | - Mengyu Li
- No.1 Middle School of Tancheng, Linyi, Shandong 276100, PR China
| | - Jianyong Feng
- National Laboratory of Solid State Microstructures, Collaborative Innovation Center of Advanced Microstructures, College of Engineering and Applied Sciences, Nanjing University, Nanjing, Jiangsu, 210093, PR China
| | - Lang Pei
- National Laboratory of Solid State Microstructures, Collaborative Innovation Center of Advanced Microstructures, College of Engineering and Applied Sciences, Nanjing University, Nanjing, Jiangsu, 210093, PR China
| | - Chenguang Zhou
- National Laboratory of Solid State Microstructures, Collaborative Innovation Center of Advanced Microstructures, College of Engineering and Applied Sciences, Nanjing University, Nanjing, Jiangsu, 210093, PR China
| | - Junkang Zhou
- Jiangsu Province Key Laboratory for Nanotechnology, Eco-Materials and Renewable Energy Research Center (ERERC), School of Physics, Nanjing University, Nanjing, Jiangsu, 210093, PR China
| | - Lingxia Yang
- National Laboratory of Solid State Microstructures, Collaborative Innovation Center of Advanced Microstructures, College of Engineering and Applied Sciences, Nanjing University, Nanjing, Jiangsu, 210093, PR China
| | - Wenchao Li
- National Laboratory of Solid State Microstructures, Collaborative Innovation Center of Advanced Microstructures, College of Engineering and Applied Sciences, Nanjing University, Nanjing, Jiangsu, 210093, PR China
| | - Guangzhou Xu
- National Laboratory of Solid State Microstructures, Collaborative Innovation Center of Advanced Microstructures, College of Engineering and Applied Sciences, Nanjing University, Nanjing, Jiangsu, 210093, PR China
| | - Shicheng Yan
- National Laboratory of Solid State Microstructures, Collaborative Innovation Center of Advanced Microstructures, College of Engineering and Applied Sciences, Nanjing University, Nanjing, Jiangsu, 210093, PR China
| | - Zhigang Zou
- National Laboratory of Solid State Microstructures, Collaborative Innovation Center of Advanced Microstructures, College of Engineering and Applied Sciences, Nanjing University, Nanjing, Jiangsu, 210093, PR China
- Jiangsu Province Key Laboratory for Nanotechnology, Eco-Materials and Renewable Energy Research Center (ERERC), School of Physics, Nanjing University, Nanjing, Jiangsu, 210093, PR China
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230
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Ghosh AB, Saha N, Sarkar A, Dutta AK, Satra J, Adhikary B. Single source precursor driven phase selective synthesis of Au–CuGaS2 heteronanostructures: an observation of plasmon enhanced photocurrent efficiency. Dalton Trans 2018; 47:1071-1081. [DOI: 10.1039/c7dt04169a] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
Coupling of metallic Au with CuGaS2, synthesized from single molecule precursor [Ga(acda)3Cu(PPh3)2]NO3, results Au–CuGaS2 heterostructure which shows remarkably high photocurrent response compared to CuGaS2.
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Affiliation(s)
- Abhisek Brata Ghosh
- Department of Chemistry
- Indian Institute of Engineering Science and Technology
- Howrah 711 103
- India
| | - Namrata Saha
- Department of Chemistry
- Indian Institute of Engineering Science and Technology
- Howrah 711 103
- India
| | - Arpita Sarkar
- Department of Chemistry
- Indian Institute of Engineering Science and Technology
- Howrah 711 103
- India
| | - Amit Kumar Dutta
- Department of Chemistry
- Indian Institute of Engineering Science and Technology
- Howrah 711 103
- India
| | - Jit Satra
- Department of Chemistry
- Indian Institute of Engineering Science and Technology
- Howrah 711 103
- India
| | - Bibhutosh Adhikary
- Department of Chemistry
- Indian Institute of Engineering Science and Technology
- Howrah 711 103
- India
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231
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Li J, Griep M, Choi Y, Chu D. Photoelectrochemical overall water splitting with textured CuBi2O4as a photocathode. Chem Commun (Camb) 2018; 54:3331-3334. [DOI: 10.1039/c7cc09041b] [Citation(s) in RCA: 54] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Tailoring CuBi2O4photocathodes demonstrates their applicability in a photoelectrochemical tandem cell for entirely solar-driven overall water splitting.
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Affiliation(s)
- Jiangtian Li
- US Army Research Laboratory
- Sensor Electronics Device Directorate
- Adelphi
- USA
| | - Mark Griep
- US Army Research Laboratory
- Weapons and Materials Research Directorate
- USA
| | - YuSong Choi
- US Army Research Laboratory
- Weapons and Materials Research Directorate
- USA
| | - Deryn Chu
- US Army Research Laboratory
- Sensor Electronics Device Directorate
- Adelphi
- USA
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232
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Wang Z, Lyu M, Chen P, Wang S, Wang L. Energy loss analysis in photoelectrochemical water splitting: a case study of hematite photoanodes. Phys Chem Chem Phys 2018; 20:22629-22635. [DOI: 10.1039/c8cp04021d] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
The energy loss of photoelectrochemical processes can be quantitatively evaluated by analyzing the decoupled photovoltaic and electrocatalytic process.
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Affiliation(s)
- Zhiliang Wang
- Nanomaterials Centre, School of Chemical Engineering and Australian Institute for Bioengineering and Nanotechnology, The University of Queensland
- Australia
| | - Miaoqiang Lyu
- Nanomaterials Centre, School of Chemical Engineering and Australian Institute for Bioengineering and Nanotechnology, The University of Queensland
- Australia
| | - Peng Chen
- Nanomaterials Centre, School of Chemical Engineering and Australian Institute for Bioengineering and Nanotechnology, The University of Queensland
- Australia
| | - Songcan Wang
- Nanomaterials Centre, School of Chemical Engineering and Australian Institute for Bioengineering and Nanotechnology, The University of Queensland
- Australia
| | - Lianzhou Wang
- Nanomaterials Centre, School of Chemical Engineering and Australian Institute for Bioengineering and Nanotechnology, The University of Queensland
- Australia
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233
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Fu S, Zhang B, Hu H, Zhang Y, Bi Y. ZnO nanowire arrays decorated with PtO nanowires for efficient solar water splitting. Catal Sci Technol 2018. [DOI: 10.1039/c8cy00656c] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Vertically-oriented PtO nanowires have been selectively grown on ZnO nanowire arrays for the first time by a light-controlled method and were utilized as highly efficient OER cocatalysts for remarkably enhancing the PEC performance of water splitting.
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Affiliation(s)
- Shurong Fu
- State Key Laboratory for Oxo Synthesis & Selective Oxidation
- National Engineering Research Center for Fine Petrochemical Intermediates
- Lanzhou Institute of Chemical Physics, CAS
- Lanzhou
- China
| | - Beibei Zhang
- State Key Laboratory for Oxo Synthesis & Selective Oxidation
- National Engineering Research Center for Fine Petrochemical Intermediates
- Lanzhou Institute of Chemical Physics, CAS
- Lanzhou
- China
| | - Hongyan Hu
- State Key Laboratory for Oxo Synthesis & Selective Oxidation
- National Engineering Research Center for Fine Petrochemical Intermediates
- Lanzhou Institute of Chemical Physics, CAS
- Lanzhou
- China
| | - Yajun Zhang
- State Key Laboratory for Oxo Synthesis & Selective Oxidation
- National Engineering Research Center for Fine Petrochemical Intermediates
- Lanzhou Institute of Chemical Physics, CAS
- Lanzhou
- China
| | - Yingpu Bi
- State Key Laboratory for Oxo Synthesis & Selective Oxidation
- National Engineering Research Center for Fine Petrochemical Intermediates
- Lanzhou Institute of Chemical Physics, CAS
- Lanzhou
- China
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234
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Biswas S, Husek J, Baker LR. Elucidating ultrafast electron dynamics at surfaces using extreme ultraviolet (XUV) reflection–absorption spectroscopy. Chem Commun (Camb) 2018; 54:4216-4230. [DOI: 10.1039/c8cc01745j] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Time-resolved XUV reflection–absorption spectroscopy probes core-to-valence transitions to reveal state-specific electron dynamics at surfaces.
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235
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Qiu P, Yang H, Song Y, Yang L, Lv L, Zhao X, Ge L, Chen C. Potent and environmental-friendly l-cysteine @ Fe2O3 nanostructure for photoelectrochemical water splitting. Electrochim Acta 2018. [DOI: 10.1016/j.electacta.2017.10.168] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
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236
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Zhao X, Hu J, Chen S, Chen Z. An investigation on the role of W doping in BiVO4 photoanodes used for solar water splitting. Phys Chem Chem Phys 2018; 20:13637-13645. [DOI: 10.1039/c8cp01316k] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
W doping has enhanced the photocurrent through increasing the carrier density and lowering surface charge transfer resistance.
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Affiliation(s)
- Xin Zhao
- School of Materials Science and Engineering
- Nanyang Technological University
- 50 Nanyang Avenue
- Singapore
- Singapore
| | - Jun Hu
- School of Materials Science and Engineering
- Nanyang Technological University
- 50 Nanyang Avenue
- Singapore
- Singapore
| | - Shi Chen
- School of Physical and Mathematical Sciences
- Nanyang Technological University
- Singapore
- Singapore
| | - Zhong Chen
- School of Materials Science and Engineering
- Nanyang Technological University
- 50 Nanyang Avenue
- Singapore
- Singapore
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237
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Zhang K, Dong T, Xie G, Guan L, Guo B, Xiang Q, Dai Y, Tian L, Batool A, Jan SU, Boddula R, Thebo AA, Gong JR. Sacrificial Interlayer for Promoting Charge Transport in Hematite Photoanode. ACS APPLIED MATERIALS & INTERFACES 2017; 9:42723-42733. [PMID: 29193959 DOI: 10.1021/acsami.7b13163] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
The semiconductor/electrolyte interface plays a crucial role in photoelectrochemical (PEC) water-splitting devices as it determines both thermodynamic and kinetic properties of the photoelectrode. Interfacial engineering is central for the device performance improvement. Taking the cheap and stable hematite (α-Fe2O3) wormlike nanostructure photoanode as a model system, we design a facile sacrificial interlayer approach to suppress the crystal overgrowth and realize Ti doping into the crystal lattice of α-Fe2O3 in one annealing step as well as to avoid the consequent anodic shift of the photocurrent onset potential, ultimately achieving five times increase in its water oxidation photocurrent compared to the bare hematite by promoting the transport of charge carriers, including both separation of photogenerated charge carriers within the bulk semiconductor and transfer of holes across the semiconductor-electrolyte interface. Our research indicates that understanding the semiconductor/electrolyte interfacial engineering mechanism is pivotal for reconciling various strategies in a beneficial way, and this simple and cost-effective method can be generalized into other systems aiming for efficient and scalable solar energy conversion.
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Affiliation(s)
- Kai Zhang
- Chinese Academy of Sciences (CAS) Center for Excellence in Nanoscience, CAS Key Laboratory of Nanosystem and Hierarchy Fabrication, National Center for Nanoscience and Technology , Beijing 100190, P. R. China
| | - Tianjiao Dong
- Chinese Academy of Sciences (CAS) Center for Excellence in Nanoscience, CAS Key Laboratory of Nanosystem and Hierarchy Fabrication, National Center for Nanoscience and Technology , Beijing 100190, P. R. China
- University of Chinese Academy of Sciences , Beijing 100049, P. R. China
| | - Guancai Xie
- Chinese Academy of Sciences (CAS) Center for Excellence in Nanoscience, CAS Key Laboratory of Nanosystem and Hierarchy Fabrication, National Center for Nanoscience and Technology , Beijing 100190, P. R. China
- University of Chinese Academy of Sciences , Beijing 100049, P. R. China
| | - Liming Guan
- Chinese Academy of Sciences (CAS) Center for Excellence in Nanoscience, CAS Key Laboratory of Nanosystem and Hierarchy Fabrication, National Center for Nanoscience and Technology , Beijing 100190, P. R. China
| | - Beidou Guo
- Chinese Academy of Sciences (CAS) Center for Excellence in Nanoscience, CAS Key Laboratory of Nanosystem and Hierarchy Fabrication, National Center for Nanoscience and Technology , Beijing 100190, P. R. China
| | - Qin Xiang
- Chinese Academy of Sciences (CAS) Center for Excellence in Nanoscience, CAS Key Laboratory of Nanosystem and Hierarchy Fabrication, National Center for Nanoscience and Technology , Beijing 100190, P. R. China
- University of Chinese Academy of Sciences , Beijing 100049, P. R. China
| | - Yawen Dai
- Chinese Academy of Sciences (CAS) Center for Excellence in Nanoscience, CAS Key Laboratory of Nanosystem and Hierarchy Fabrication, National Center for Nanoscience and Technology , Beijing 100190, P. R. China
- University of Chinese Academy of Sciences , Beijing 100049, P. R. China
| | - Liangqiu Tian
- Chinese Academy of Sciences (CAS) Center for Excellence in Nanoscience, CAS Key Laboratory of Nanosystem and Hierarchy Fabrication, National Center for Nanoscience and Technology , Beijing 100190, P. R. China
- University of Chinese Academy of Sciences , Beijing 100049, P. R. China
| | - Aisha Batool
- Chinese Academy of Sciences (CAS) Center for Excellence in Nanoscience, CAS Key Laboratory of Nanosystem and Hierarchy Fabrication, National Center for Nanoscience and Technology , Beijing 100190, P. R. China
- University of Chinese Academy of Sciences , Beijing 100049, P. R. China
| | - Saad Ullah Jan
- Chinese Academy of Sciences (CAS) Center for Excellence in Nanoscience, CAS Key Laboratory of Nanosystem and Hierarchy Fabrication, National Center for Nanoscience and Technology , Beijing 100190, P. R. China
- University of Chinese Academy of Sciences , Beijing 100049, P. R. China
| | - Rajender Boddula
- Chinese Academy of Sciences (CAS) Center for Excellence in Nanoscience, CAS Key Laboratory of Nanosystem and Hierarchy Fabrication, National Center for Nanoscience and Technology , Beijing 100190, P. R. China
- University of Chinese Academy of Sciences , Beijing 100049, P. R. China
| | - Akbar Ali Thebo
- Chinese Academy of Sciences (CAS) Center for Excellence in Nanoscience, CAS Key Laboratory of Nanosystem and Hierarchy Fabrication, National Center for Nanoscience and Technology , Beijing 100190, P. R. China
- University of Chinese Academy of Sciences , Beijing 100049, P. R. China
| | - Jian Ru Gong
- Chinese Academy of Sciences (CAS) Center for Excellence in Nanoscience, CAS Key Laboratory of Nanosystem and Hierarchy Fabrication, National Center for Nanoscience and Technology , Beijing 100190, P. R. China
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238
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Zhao Q, Yao W, Huang C, Wu Q, Xu Q. Effective and Durable Co Single Atomic Cocatalysts for Photocatalytic Hydrogen Production. ACS APPLIED MATERIALS & INTERFACES 2017; 9:42734-42741. [PMID: 29160057 DOI: 10.1021/acsami.7b13566] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
This research reports for the first time that single cobalt atoms anchored in nitrogen-doped graphene (Co-NG) can serve as a highly effective and durable cocatalyst for visible light photocatalytic hydrogen production from water. Results show that, under identical conditions, the hydrogen production rate (1382 μmol/h) for 0.25 wt % Co-NG-loaded CdS photocatalyst (0.25 wt % Co-NG/CdS) is 3.42 times greater than that of nitrogen-doped graphene (NG) loaded CdS photocatalyst (NG/CdS) and about 1.3 times greater than the greatest hydrogen production rate (1077 μmol/h) for 1.5 wt % Pt nanoparticle loaded CdS photocatalyst (1.5 wt % Pt-NPs/CdS). At 420 nm irradiation, the quantum efficiency of the 0.25 wt % Co-NG/CdS photocatalyst is 50.5%, the highest efficiency among those literature-reported non-noble metal cocatalysts. The Co-NG/CdS nanocomposite-based photocatalyst also has an extended durability. No activity decline was detected during three cyclic photocatalytic life span tests. The very low cocatalyst loading, along with the facile preparation technology for this non-noble metal cocatalyst, will significantly reduce the hydrogen production costs and finally lead to the commercialization of the solar catalytic hydrogen production process. Based on experimental results, we conclude that Co-NG can successfully replace noble metal cocatalysts as a highly effective and durable cocatalyst for renewable solar hydrogen production. This finding will point to a new way for the development of highly effective, long life span, non-noble metal-based cocatalysts for renewable and cost-effective hydrogen production.
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Affiliation(s)
- Qi Zhao
- Shanghai Key Laboratory of Materials Protection and Advanced Materials in Electric Power, College of Environmental and Chemical Engineering, Shanghai University of Electric Power , Shanghai 200090, P. R. China
| | - Weifeng Yao
- Shanghai Key Laboratory of Materials Protection and Advanced Materials in Electric Power, College of Environmental and Chemical Engineering, Shanghai University of Electric Power , Shanghai 200090, P. R. China
| | - Cunping Huang
- Aviation Fuels Research Laboratory, Federal Aviation Administration William J. Hughes Technical Center, Atlantic City International Airport , Atlantic City, New Jersey 08405, United States
| | - Qiang Wu
- Shanghai Key Laboratory of Materials Protection and Advanced Materials in Electric Power, College of Environmental and Chemical Engineering, Shanghai University of Electric Power , Shanghai 200090, P. R. China
| | - Qunjie Xu
- Shanghai Key Laboratory of Materials Protection and Advanced Materials in Electric Power, College of Environmental and Chemical Engineering, Shanghai University of Electric Power , Shanghai 200090, P. R. China
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239
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Kaneko H, Minegishi T, Domen K. Recent Progress in the Surface Modification of Photoelectrodes toward Efficient and Stable Overall Water Splitting. Chemistry 2017; 24:5697-5706. [DOI: 10.1002/chem.201703104] [Citation(s) in RCA: 40] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2017] [Indexed: 11/10/2022]
Affiliation(s)
- Hiroyuki Kaneko
- Department of Chemical System Engineering; The University of Tokyo; 7-3-1 Hongo Bunkyo-ku Tokyo 113-8656 Japan
| | - Tsutomu Minegishi
- Department of Chemical System Engineering; The University of Tokyo; 7-3-1 Hongo Bunkyo-ku Tokyo 113-8656 Japan
- JST; PRESTO; 7-3-1 Hongo Bunkyo-ku Tokyo 113-8656 Japan
| | - Kazunari Domen
- Department of Chemical System Engineering; The University of Tokyo; 7-3-1 Hongo Bunkyo-ku Tokyo 113-8656 Japan
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240
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Li J, Lei N, Guo L, Song Q, Liang Z. Constructing h-BN/Bi2
WO6
Quantum Dot Hybrid with Fast Charge Separation and Enhanced Photoelectrochemical Performance by using h-BN for Hole Transfer. ChemElectroChem 2017. [DOI: 10.1002/celc.201701056] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
Affiliation(s)
- Junqi Li
- School of Materials Science and Engineering; Shaanxi University of Science and Technology; Xi'an 710021 P. R. China
| | - Nan Lei
- School of Materials Science and Engineering; Shaanxi University of Science and Technology; Xi'an 710021 P. R. China
| | - Liu Guo
- School of Materials Science and Engineering; Shaanxi University of Science and Technology; Xi'an 710021 P. R. China
| | - Qianqian Song
- School of Materials Science and Engineering; Shaanxi University of Science and Technology; Xi'an 710021 P. R. China
| | - Zheng Liang
- School of Materials Science and Engineering; Shaanxi University of Science and Technology; Xi'an 710021 P. R. China
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241
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Cobalt oxide and carbon modified hematite nanorod arrays for improved photoelectrochemical water splitting. CHINESE CHEM LETT 2017. [DOI: 10.1016/j.cclet.2017.11.037] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
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242
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The electrochemistry of iron oxide thin films nanostructured by high ion flux plasma exposure. Electrochim Acta 2017. [DOI: 10.1016/j.electacta.2017.11.117] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
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243
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Antuch M, Millet P, Iwase A, Kudo A, Grigoriev SA, Voloshin YZ. Characterization of Rh:SrTiO3 photoelectrodes surface-modified with a cobalt clathrochelate and their application to the hydrogen evolution reaction. Electrochim Acta 2017. [DOI: 10.1016/j.electacta.2017.10.018] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
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244
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Zhang Y, He S, Guo W, Hu Y, Huang J, Mulcahy JR, Wei WD. Surface-Plasmon-Driven Hot Electron Photochemistry. Chem Rev 2017; 118:2927-2954. [DOI: 10.1021/acs.chemrev.7b00430] [Citation(s) in RCA: 730] [Impact Index Per Article: 104.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
Affiliation(s)
- Yuchao Zhang
- Department of Chemistry and Center for Catalysis, University of Florida, Gainesville, Florida 32611, United States
| | - Shuai He
- Department of Chemistry and Center for Catalysis, University of Florida, Gainesville, Florida 32611, United States
| | - Wenxiao Guo
- Department of Chemistry and Center for Catalysis, University of Florida, Gainesville, Florida 32611, United States
| | - Yue Hu
- Department of Chemistry and Center for Catalysis, University of Florida, Gainesville, Florida 32611, United States
| | - Jiawei Huang
- Department of Chemistry and Center for Catalysis, University of Florida, Gainesville, Florida 32611, United States
| | - Justin R. Mulcahy
- Department of Chemistry and Center for Catalysis, University of Florida, Gainesville, Florida 32611, United States
| | - Wei David Wei
- Department of Chemistry and Center for Catalysis, University of Florida, Gainesville, Florida 32611, United States
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245
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Peter LM, Wong LH, Abdi FF. Revealing the Influence of Doping and Surface Treatment on the Surface Carrier Dynamics in Hematite Nanorod Photoanodes. ACS APPLIED MATERIALS & INTERFACES 2017; 9:41265-41272. [PMID: 29099583 DOI: 10.1021/acsami.7b13263] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
Photoelectrochemical (PEC) water oxidation is considered to be the rate-limiting step of the two half-reactions in light-driven water splitting. Consequently, considerable effort has focused on improving the performance of photoanodes for water oxidation. While these efforts have met with some success, the mechanisms responsible for improvements resulting from photoanode modifications are often difficult to determine. This is mainly caused by the entanglement of numerous properties that influence the PEC performance, particularly processes that occur at the photoanode/electrolyte interface. In this study, we set out to elucidate the effects on the surface carrier dynamics of hematite photoanodes of introducing manganese (Mn) into hematite nanorods and of creating a core-shell structure. Intensity-modulated photocurrent spectroscopy (IMPS) measurements reveal that the introduction of Mn into hematite not only increases the rate constant for hole transfer but also reduces the rate constant for surface recombination. In contrast, the core-shell architecture evidently passivates the surface states where recombination occurs; no change is observed for the charge transfer rate constant, whereas the surface recombination rate constant is suppressed by ∼1 order of magnitude.
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Affiliation(s)
- Laurence M Peter
- Department of Chemistry, University of Bath , Bath BA2 7AY, United Kingdom
| | - Lydia H Wong
- School of Materials Science and Engineering, Nanyang Technological University , Nanyang Avenue, Singapore 639798
| | - Fatwa F Abdi
- Institute for Solar Fuels, Helmholtz-Zentrum Berlin für Materialien und Energie GmbH , Hahn-Meitner-Platz 1, Berlin 14109, Germany
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246
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Hegner FS, Cardenas-Morcoso D, Giménez S, López N, Galan-Mascaros JR. Level Alignment as Descriptor for Semiconductor/Catalyst Systems in Water Splitting: The Case of Hematite/Cobalt Hexacyanoferrate Photoanodes. CHEMSUSCHEM 2017; 10:4552-4560. [PMID: 28967707 DOI: 10.1002/cssc.201701538] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/15/2017] [Revised: 09/29/2017] [Indexed: 06/07/2023]
Abstract
The realization of artificial photosynthesis may depend on the efficient integration of photoactive semiconductors and catalysts to promote photoelectrochemical water splitting. Many efforts are currently devoted to the processing of multicomponent anodes and cathodes in the search for appropriate synergy between light absorbers and active catalysts. No single material appears to combine both features. Many experimental parameters are key to achieve the needed synergy between both systems, without clear protocols for success. Herein, we show how computational chemistry can shed some light on this cumbersome problem. DFT calculations are useful to predict adequate energy-level alignment for thermodynamically favored hole transfer. As proof of concept, we experimentally confirmed the limited performance enhancement in hematite photoanodes decorated with cobalt hexacyanoferrate as a competent water-oxidation catalyst. Computational methods describe the misalignment of their energy levels, which is the origin of this mismatch. Photoelectrochemical studies indicate that the catalyst exclusively shifts the hematite surface state to lower potentials, which therefore reduces the onset for water oxidation. Although kinetics will still depend on interface architecture, our simple theoretical approach may identify and predict plausible semiconductor/catalyst combinations, which will speed up experimental work towards promising photoelectrocatalytic systems.
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Affiliation(s)
- Franziska Simone Hegner
- Institute of Chemical Research of Catalonia (ICIQ), Av. Paisos Catalans, 16, Tarragona, 43007, Spain
| | | | - Sixto Giménez
- Institute of Advanced Materials (INAM), Universitat Jaume I, Castellon, 12006, Spain
| | - Núria López
- Institute of Chemical Research of Catalonia (ICIQ), Av. Paisos Catalans, 16, Tarragona, 43007, Spain
| | - Jose Ramon Galan-Mascaros
- Institute of Chemical Research of Catalonia (ICIQ), Av. Paisos Catalans, 16, Tarragona, 43007, Spain
- ICREA, Pg. Lluís Companys, 23., Barcelona, 08010, Spain
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247
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Seriani N. Ab initio simulations of water splitting on hematite. JOURNAL OF PHYSICS. CONDENSED MATTER : AN INSTITUTE OF PHYSICS JOURNAL 2017; 29:463002. [PMID: 29057752 DOI: 10.1088/1361-648x/aa84d9] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
In recent years, hematite has attracted great interest as a photocatalyst for water splitting, but many questions remain unanswered about the mechanisms and the main limiting factors. For this reason, density functional theory has been used to understand the optical, electronic and chemical properties of this material at an atomistic level. Bulk doping can be used to reduce the band gap, and to increase photoabsorption and charge mobility. Charge transport takes place through adiabatic polaron hopping. The stable (0 0 0 1) surface has a stoichiometric termination when exposed to oxygen, it becomes hydroxylated in water, and it has an oxygen-rich termination under illumination in a photoelectrochemical setup. On the oxygen-rich termination, surface states are present that might act as recombination centres for electrons and holes. On the contrary, on the hydroxylated termination surface states appear only on reaction intermediates. The intrinsic surface states disappear in the presence of an overlayer of gallium oxide. The reaction of water oxidation is assumed to proceed by four proton-coupled electron transfers and it is shown to involve a nucleophilic attack with the formation of an OOH group. Calculated overpotentials are in the range of 0.5-0.6 V. Open questions and future research directions are briefly discussed.
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Affiliation(s)
- Nicola Seriani
- The Abdus Salam ICTP, Strada Costiera 11, 34151 Trieste, Italy
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248
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Shavorskiy A, Ye X, Karslıoğlu O, Poletayev AD, Hartl M, Zegkinoglou I, Trotochaud L, Nemšák S, Schneider CM, Crumlin EJ, Axnanda S, Liu Z, Ross PN, Chueh W, Bluhm H. Direct Mapping of Band Positions in Doped and Undoped Hematite during Photoelectrochemical Water Splitting. J Phys Chem Lett 2017; 8:5579-5586. [PMID: 29083905 DOI: 10.1021/acs.jpclett.7b02548] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
Photoelectrochemical water splitting is a promising pathway for the direct conversion of renewable solar energy to easy to store and use chemical energy. The performance of a photoelectrochemical device is determined in large part by the heterogeneous interface between the photoanode and the electrolyte, which we here characterize directly under operating conditions using interface-specific probes. Utilizing X-ray photoelectron spectroscopy as a noncontact probe of local electrical potentials, we demonstrate direct measurements of the band alignment at the semiconductor/electrolyte interface of an operating hematite/KOH photoelectrochemical cell as a function of solar illumination, applied potential, and doping. We provide evidence for the absence of in-gap states in this system, which is contrary to previous measurements using indirect methods, and give a comprehensive description of shifts in the band positions and limiting processes during the photoelectrochemical reaction.
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Affiliation(s)
- Andrey Shavorskiy
- Chemical Sciences Division, Lawrence Berkeley National Laboratory , Berkeley, California 94720, United States
| | - Xiaofei Ye
- Material Science and Engineering Division, Stanford University , Stanford, California 94305, United States
| | - Osman Karslıoğlu
- Chemical Sciences Division, Lawrence Berkeley National Laboratory , Berkeley, California 94720, United States
| | - Andrey D Poletayev
- Material Science and Engineering Division, Stanford University , Stanford, California 94305, United States
| | - Matthias Hartl
- Chemical Sciences Division, Lawrence Berkeley National Laboratory , Berkeley, California 94720, United States
| | - Ioannis Zegkinoglou
- Chemical Sciences Division, Lawrence Berkeley National Laboratory , Berkeley, California 94720, United States
| | - Lena Trotochaud
- Chemical Sciences Division, Lawrence Berkeley National Laboratory , Berkeley, California 94720, United States
| | - Slavomir Nemšák
- Chemical Sciences Division, Lawrence Berkeley National Laboratory , Berkeley, California 94720, United States
| | - Claus M Schneider
- Peter-Grünberg-Institut-6, Forschungszentrum Jülich , 52425 Jülich, Germany
| | - Ethan J Crumlin
- Advanced Light Source, Lawrence Berkeley National Laboratory , Berkeley, California 94720, United States
| | - Stephanus Axnanda
- Advanced Light Source, Lawrence Berkeley National Laboratory , Berkeley, California 94720, United States
| | - Zhi Liu
- Advanced Light Source, Lawrence Berkeley National Laboratory , Berkeley, California 94720, United States
| | - Philip N Ross
- Materials Sciences Division, Lawrence Berkeley National Laboratory , Berkeley, California 94720, United States
| | - William Chueh
- Material Science and Engineering Division, Stanford University , Stanford, California 94305, United States
| | - Hendrik Bluhm
- Chemical Sciences Division, Lawrence Berkeley National Laboratory , Berkeley, California 94720, United States
- Advanced Light Source, Lawrence Berkeley National Laboratory , Berkeley, California 94720, United States
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249
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Anderson NC, Carroll GM, Pekarek RT, Christensen ST, van de Lagemaat J, Neale NR. Silicon Photoelectrode Thermodynamics and Hydrogen Evolution Kinetics Measured by Intensity-Modulated High-Frequency Resistivity Impedance Spectroscopy. J Phys Chem Lett 2017; 8:5253-5258. [PMID: 28981282 DOI: 10.1021/acs.jpclett.7b01311] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
We present an impedance technique based on light intensity-modulated high-frequency resistivity (IMHFR) that provides a new way to elucidate both the thermodynamics and kinetics in complex semiconductor photoelectrodes. We apply IMHFR to probe electrode interfacial energetics on oxide-modified semiconductor surfaces frequently used to improve the stability and efficiency of photoelectrochemical water splitting systems. Combined with current density-voltage measurements, the technique quantifies the overpotential for proton reduction relative to its thermodynamic potential in Si photocathodes coated with three oxides (SiOx, TiO2, and Al2O3) and a Pt catalyst. In pH 7 electrolyte, the flatband potentials of TiO2- and Al2O3-coated Si electrodes are negative relative to samples with native SiOx, indicating that SiOx is a better protective layer against oxidative electrochemical corrosion than ALD-deposited crystalline TiO2 or Al2O3. Adding a Pt catalyst to SiOx/Si minimizes proton reduction overpotential losses but at the expense of a reduction in available energy characterized by a more negative flatband potential relative to catalyst-free SiOx/Si.
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Affiliation(s)
- Nicholas C Anderson
- Chemistry and Nanoscience Center, National Renewable Energy Laboratory , 15013 Denver West Parkway, Golden, Colorado 80401, United States
| | - Gerard M Carroll
- Chemistry and Nanoscience Center, National Renewable Energy Laboratory , 15013 Denver West Parkway, Golden, Colorado 80401, United States
| | - Ryan T Pekarek
- Chemistry and Nanoscience Center, National Renewable Energy Laboratory , 15013 Denver West Parkway, Golden, Colorado 80401, United States
- Department of Chemistry, The University of Texas at Austin , 2506 Speedway STOP A5300, Austin, Texas 78712, United States
| | - Steven T Christensen
- Materials Science Center, National Renewable Energy Laboratory , 15013 Denver West Parkway, Golden, Colorado 80401, United States
| | - Jao van de Lagemaat
- Chemistry and Nanoscience Center, National Renewable Energy Laboratory , 15013 Denver West Parkway, Golden, Colorado 80401, United States
| | - Nathan R Neale
- Chemistry and Nanoscience Center, National Renewable Energy Laboratory , 15013 Denver West Parkway, Golden, Colorado 80401, United States
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Ghosh S, Soudackov AV, Hammes-Schiffer S. Role of Proton Diffusion in the Nonexponential Kinetics of Proton-Coupled Electron Transfer from Photoreduced ZnO Nanocrystals. ACS NANO 2017; 11:10295-10302. [PMID: 28925682 DOI: 10.1021/acsnano.7b05009] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
Experiments have suggested that photoreduced ZnO nanocrystals transfer an electron and a proton to organic radicals through a concerted proton-coupled electron transfer (PCET) mechanism. The kinetics of this process was studied by monitoring the decay of the absorbance that reflects the concentration of electrons in the conduction bands of the nanocrystals. Interestingly, this absorbance exhibited nonexponential decay kinetics that could not be explained by heterogeneities of the nanoparticles or electron content. To determine if proton diffusion from inside the nanocrystal to reactive sites on the surface could lead to such nonexponential kinetics, herein this process is modeled using kinetic Monte Carlo simulations. These simulations provide the survival probability of a proton hopping among bulk, subsurface, and surface sites within the nanocrystal until it reaches a reactive surface site where it transfers to an organic radical. Using activation barriers predominantly obtained from periodic density functional theory, the simulations reproduce the nonexponential decay kinetics. This nonexponential behavior is found to arise from the broad distribution of lifetimes caused by different types of subsurface and surface sites. The longer lifetimes are associated with the proton becoming temporarily trapped in a subsurface site that does not have direct access to a reactive surface site due to capping ligands. These calculations suggest that movement of the protons rather than the electrons dominate the nonexponential kinetics of the PCET reaction. Thus, the impact of both bulk and surface properties of metal-oxide nanoparticles on proton conductivity should be considered when designing heterogeneous catalysts.
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Affiliation(s)
- Soumya Ghosh
- Department of Chemistry, 600 South Mathews Avenue, University of Illinois at Urbana-Champaign , Urbana, Illinois 61801, United States
| | - Alexander V Soudackov
- Department of Chemistry, 600 South Mathews Avenue, University of Illinois at Urbana-Champaign , Urbana, Illinois 61801, United States
| | - Sharon Hammes-Schiffer
- Department of Chemistry, 600 South Mathews Avenue, University of Illinois at Urbana-Champaign , Urbana, Illinois 61801, United States
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