1
|
Nassereddine Y, Benyoussef M, Rajput NS, Saitzek S, El Marssi M, Jouiad M. Strong Intermixing Effects of LFO 1-x/STO x toward the Development of Efficient Photoanodes for Photoelectrocatalytic Applications. NANOMATERIALS (BASEL, SWITZERLAND) 2023; 13:2863. [PMID: 37947708 PMCID: PMC10649736 DOI: 10.3390/nano13212863] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/30/2023] [Revised: 10/26/2023] [Accepted: 10/28/2023] [Indexed: 11/12/2023]
Abstract
Aiming to improve the photocatalytic properties of transition metal perovskites to be used as robust photoanodes, [LaFeO3]1-x/[SrTiO3]x nanocomposites (LFO1-x/STOx) are considered. This hybrid structure combines good semiconducting properties and an interesting intrinsic remanent polarization. All the studied samples were fabricated using a solid-state method followed by high-energy ball milling, and they were subsequently deposited by spray coating. The synthesized compounds were demonstrated to possess orthorhombic (Pnma) and cubic (Pm3¯m) structures for LFO and STO, respectively, with an average grain size of 55-70 nm. The LFO1-x/STOx nanocomposites appeared to exhibit high visible light absorption, corresponding to band gaps of 2.17-3.21 eV. Our findings show that LFO0.5/STO0.5 is the optimized heterostructure; it achieved a high photocurrent density of 11 μA/cm2 at 1.23 V bias vs. RHE and an applied bias photo-to-current efficiency of 4.1 × 10-3% at 0.76 V vs. RHE, as demonstrated by the photoelectrochemical measurements. These results underline the role of the two phases intermixing LFO and STO at the appropriate content to yield a high-performing photoanode ascribed to efficient charge separation and transfer. This suggests that LFO0.5/STO0.5 could be a potential candidate for the development of efficient photoanodes for hydrogen generation via photoelectrocatalytic water splitting.
Collapse
Affiliation(s)
- Yassine Nassereddine
- Laboratory of Physics of Condensed Matter, University of Picardie Jules Verne, Scientific Pole, 33 Rue Saint-Leu, CEDEX 1, 80039 Amiens, France; (Y.N.)
| | - Manal Benyoussef
- Laboratory of Physics of Condensed Matter, University of Picardie Jules Verne, Scientific Pole, 33 Rue Saint-Leu, CEDEX 1, 80039 Amiens, France; (Y.N.)
| | - Nitul S. Rajput
- Advanced Materials Research Center, Technology Innovation Institute, Abu Dhabi P.O. Box 9639, United Arab Emirates
| | - Sébastien Saitzek
- Catalyse et Chimie du Solide (UCCS), University of Artois, CNRS, Centrale Lille, ENSCL, UMR 8181, 62300 Lens, France
| | - Mimoun El Marssi
- Laboratory of Physics of Condensed Matter, University of Picardie Jules Verne, Scientific Pole, 33 Rue Saint-Leu, CEDEX 1, 80039 Amiens, France; (Y.N.)
| | - Mustapha Jouiad
- Laboratory of Physics of Condensed Matter, University of Picardie Jules Verne, Scientific Pole, 33 Rue Saint-Leu, CEDEX 1, 80039 Amiens, France; (Y.N.)
| |
Collapse
|
2
|
Sun X, Lan Z, Wang M, Geng Q, Lv X, Li M. Multifunctional Role of Ag-Substitution in Enhancing the Photoelectrochemical Properties of LaFeO 3 Photocathodes. CHEMSUSCHEM 2023; 16:e202300645. [PMID: 37438975 DOI: 10.1002/cssc.202300645] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/04/2023] [Revised: 06/17/2023] [Accepted: 07/10/2023] [Indexed: 07/14/2023]
Abstract
Earth-abundant LaFeO3 is a promising p-type semiconductor for photoelectrochemical cells due to its stable photoresponses, high photovoltages and appropriate band alignments, but the photoelectrochemical properties of LaFeO3 , especially the incident-photon-to-current conversion efficiency, need to be further improved. Herein, we propose to partially substitute La3+ of LaFeO3 with Ag+ to enhance the photoelectrochemical performance of LaFeO3 . The combined experimental and computational studies show that Ag-substitution improves surface charge transfer kinetics through introducing active electronic states and increasing electrochemically active surface areas. Furthermore, Ag-substitution decreases grain boundary number and increases majority carrier density, which promotes bulk charge transports. Ag-substitution also reduces the bandgap energy, increasing the flux of carriers involved in photoelectrochemical reactions. As a result, after 8 % Ag-substitution, the photocurrent density of LaFeO3 is enhanced by more than 6 times (-0.64 mA cm-2 at 0.5 V vs RHE) in the presence of oxygen, which is the highest photocurrent gain compared with other cation substitution or doping. The corresponding photocurrent onset potential also demonstrates a positive shift of 30 mV. This work highlights the versatile effects of Ag-substitution on the photoelectrochemical properties of LaFeO3 , which can provide useful insights into the mechanism of enhanced photoelectrochemical performance by doping or substitution.
Collapse
Affiliation(s)
- Xin Sun
- State Key Laboratory of Alternate Electrical Power System with Renewable Energy Sources, School of New Energy, North China Electric Power University, Beijing, 102206, China
| | - Zhineng Lan
- State Key Laboratory of Alternate Electrical Power System with Renewable Energy Sources, School of New Energy, North China Electric Power University, Beijing, 102206, China
| | - Min Wang
- State Key Laboratory of Alternate Electrical Power System with Renewable Energy Sources, School of New Energy, North China Electric Power University, Beijing, 102206, China
| | - Qi Geng
- State Key Laboratory of Alternate Electrical Power System with Renewable Energy Sources, School of New Energy, North China Electric Power University, Beijing, 102206, China
| | - Xiaojun Lv
- State Key Laboratory of Alternate Electrical Power System with Renewable Energy Sources, School of New Energy, North China Electric Power University, Beijing, 102206, China
| | - Meicheng Li
- State Key Laboratory of Alternate Electrical Power System with Renewable Energy Sources, School of New Energy, North China Electric Power University, Beijing, 102206, China
| |
Collapse
|
3
|
Chertkova VP, Iskortseva AN, Pazhetnov EM, Arkharova NA, Ryazantsev SV, Levin EE, Nikitina VA. Evaluation of the Efficiency of Photoelectrochemical Activity Enhancement for the Nanostructured LaFeO 3 Photocathode by Surface Passivation and Co-Catalyst Deposition. NANOMATERIALS (BASEL, SWITZERLAND) 2022; 12:nano12234327. [PMID: 36500950 PMCID: PMC9741200 DOI: 10.3390/nano12234327] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/10/2022] [Revised: 11/29/2022] [Accepted: 12/02/2022] [Indexed: 06/01/2023]
Abstract
Perovskite-type lanthanum iron oxide, LaFeO3, is a promising photocathode material that can achieve water splitting under visible light. However, the performance of this photoelectrode material is limited by significant electron-hole recombination. In this work, we explore different strategies to optimize the activity of a nanostructured porous LaFeO3 film, which demonstrates enhanced photoelectrocatalytic activity due to the reduced diffusion length of the charge carriers. We found that surface passivation is not an efficient approach for enhancing the photoelectrochemical performance of LaFeO3, as it is sufficiently stable under photoelectrocatalytic conditions. Instead, the deposition of a Pt co-catalyst was shown to be essential for maximizing the photoelectrochemical activity both in hydrogen evolution and oxygen reduction reactions. Illumination-induced band edge unpinning was found to be a major challenge for the further development of LaFeO3 photocathodes for water-splitting applications.
Collapse
Affiliation(s)
| | - Aleksandra N. Iskortseva
- Department of Chemistry, Lomonosov Moscow State University, Moscow 119991, Russia
- Center for Energy Science and Technology, Skolkovo Institute of Science and Technology, Moscow 121205, Russia
| | - Egor M. Pazhetnov
- Center for Energy Science and Technology, Skolkovo Institute of Science and Technology, Moscow 121205, Russia
| | | | - Sergey V. Ryazantsev
- Department of Chemistry, Lomonosov Moscow State University, Moscow 119991, Russia
- Center for Energy Science and Technology, Skolkovo Institute of Science and Technology, Moscow 121205, Russia
| | - Eduard E. Levin
- Department of Chemistry, Lomonosov Moscow State University, Moscow 119991, Russia
- FSRC “Crystallography and Photonics” RAS, Moscow 119333, Russia
| | - Victoria A. Nikitina
- Department of Chemistry, Lomonosov Moscow State University, Moscow 119991, Russia
- Center for Energy Science and Technology, Skolkovo Institute of Science and Technology, Moscow 121205, Russia
| |
Collapse
|
4
|
Sun X, Tiwari D, Li M, Fermin DJ. Decoupling the impact of bulk and surface point defects on the photoelectrochemical properties of LaFeO 3 thin films. Chem Sci 2022; 13:11252-11259. [PMID: 36320475 PMCID: PMC9517707 DOI: 10.1039/d2sc04675j] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2022] [Accepted: 09/05/2022] [Indexed: 11/21/2022] Open
Abstract
Point defects (PDs) play a key role in the properties of semiconductor photoelectrodes, from doping density to carrier mobility and lifetime. Although this issue has been extensively investigated in the context of photovoltaic absorbers, the role of PDs in photoelectrodes for solar fuels remains poorly understood. In perovskite oxides such as LaFeO3 (LFO), PDs can be tuned by changing the cation ratio, cation substitution and oxygen content. In this paper, we report the first study on the impact of bulk and surface PDs on the photoelectrochemical properties of LFO thin films. We independently varied the La : Fe ratio, within 10% of the stoichiometric value, in the bulk and at the surface by tuning the precursor composition as well as selective acid etching. The structure and composition of thin films deposited by sol–gel methods were investigated by SEM-EDX, ICP-OES, XPS and XRD. Our analysis shows a correlation between the binding energies of Fe 2p3/2 and O 1s, establishing a link between the oxidation state of Fe and the covalency of the Fe–O bond. Electrochemical studies reveal the emergence of electronic states close to the valence band edge with decreasing bulk Fe content. DFT calculations confirm that Fe vacancies generate states located near the valence band, which act as hole-traps and recombination sites under illumination. Dynamic photocurrent responses associated with oxygen reduction and hydrogen evolution show that the stoichiometric La : Fe ratio provides the most photoactive oxide; however, this can only be achieved by independently tuning the bulk and surface compositions of the oxide. This article shows, for the first time, the delicate balance between controlling bulk recombination sites and dynamics of interfacial carrier transfer via independently tuning the bulk and surface compositions of perovskite oxide thin films.![]()
Collapse
Affiliation(s)
- Xin Sun
- State Key Laboratory of Alternate Electrical Power System with Renewable Energy Sources, School of New Energy, North China Electric Power University, Beijing, 102206, China
| | - Devendra Tiwari
- Department of Mathematics, Physics and Electrical Engineering, Northumbria University, Ellison Building, Newcastle Upon Tyne, NE1 8ST, UK
- School of Chemistry, University of Bristol, Cantocks Close, Bristol BS8 1TS, UK
| | - Meicheng Li
- State Key Laboratory of Alternate Electrical Power System with Renewable Energy Sources, School of New Energy, North China Electric Power University, Beijing, 102206, China
| | - David J. Fermin
- School of Chemistry, University of Bristol, Cantocks Close, Bristol BS8 1TS, UK
| |
Collapse
|
5
|
Nkwachukwu OV, Arotiba OA. Perovskite Oxide-Based Materials for Photocatalytic and Photoelectrocatalytic Treatment of Water. Front Chem 2021; 9:634630. [PMID: 33937190 PMCID: PMC8082458 DOI: 10.3389/fchem.2021.634630] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2020] [Accepted: 02/19/2021] [Indexed: 11/13/2022] Open
Abstract
Meeting the global challenge of water availability necessitates diversification from traditional water treatment methods to other complementary methods, such as photocatalysis and photoelectrocatalysis (PEC), for a more robust solution. Materials play very important roles in the development of these newer methods. Thus, the quest and applications of a myriad of materials are ongoing areas of water research. Perovskite and perovskite-related materials, which have been largely explored in the energy sectors, are potential materials in water treatment technologies. In this review, attention is paid to the recent progress in the application of perovskite materials in photocatalytic and photoelectrocatalytic degradation of organic pollutants in water. Water treatment applications of lanthanum, ferrite, titanate, and tantalum (and others)-based perovskites are discussed. The chemical nature and different synthetic routes of perovskites or perovskite composites are presented as fundamental to applications.
Collapse
Affiliation(s)
- Oluchi V. Nkwachukwu
- Department of Chemical Sciences, University of Johannesburg, Johannesburg, South Africa
| | - Omotayo A. Arotiba
- Department of Chemical Sciences, University of Johannesburg, Johannesburg, South Africa
- Centre for Nanomaterials Science Research, University of Johannesburg, Johannesburg, South Africa
| |
Collapse
|
6
|
Andrei F, Zăvoianu R, Marcu IC. Complex Catalytic Materials Based on the Perovskite-Type Structure for Energy and Environmental Applications. MATERIALS (BASEL, SWITZERLAND) 2020; 13:E5555. [PMID: 33291516 PMCID: PMC7730792 DOI: 10.3390/ma13235555] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/12/2020] [Revised: 12/01/2020] [Accepted: 12/03/2020] [Indexed: 12/27/2022]
Abstract
This review paper focuses on perovskite-type materials as (photo)catalysts for energy and environmental applications. After a short introduction and the description of the structure of inorganic and hybrid organic-inorganic perovskites, the methods of preparation of inorganic perovskites both as powders via chemical routes and as thin films via laser-based techniques are tackled with, for the first, an analysis of the influence of the preparation method on the specific surface area of the material obtained. Then, the (photo)catalytic applications of the perovskites in energy production either in the form of hydrogen via water photodecomposition or by methane combustion, and in the removal of organic pollutants from waste waters, are reviewed.
Collapse
Affiliation(s)
- Florin Andrei
- Laboratory of Chemical Technology & Catalysis, Department of Organic Chemistry, Biochemistry & Catalysis, Faculty of Chemistry, University of Bucharest, 4-12, Blv. Regina Elisabeta, 030018 Bucharest, Romania;
- Interdisciplinary Innovation Center of Photonics and Plasma for Eco-Nano Technologies and Advanced Materials, National Institute for Laser, Plasma and Radiation Physics, 409 Atomistilor Street, 077125 Magurele, Romania
| | - Rodica Zăvoianu
- Laboratory of Chemical Technology & Catalysis, Department of Organic Chemistry, Biochemistry & Catalysis, Faculty of Chemistry, University of Bucharest, 4-12, Blv. Regina Elisabeta, 030018 Bucharest, Romania;
- Research Center for Catalysts and Catalytic Processes, Faculty of Chemistry, University of Bucharest, 4-12 Blv Regina Elisabeta, 030018 Bucharest, Romania
| | - Ioan-Cezar Marcu
- Laboratory of Chemical Technology & Catalysis, Department of Organic Chemistry, Biochemistry & Catalysis, Faculty of Chemistry, University of Bucharest, 4-12, Blv. Regina Elisabeta, 030018 Bucharest, Romania;
- Research Center for Catalysts and Catalytic Processes, Faculty of Chemistry, University of Bucharest, 4-12 Blv Regina Elisabeta, 030018 Bucharest, Romania
| |
Collapse
|
7
|
Sun X, Tiwari D, Fermin DJ. Promoting Active Electronic States in LaFeO 3 Thin-Films Photocathodes via Alkaline-Earth Metal Substitution. ACS APPLIED MATERIALS & INTERFACES 2020; 12:31486-31495. [PMID: 32539332 DOI: 10.1021/acsami.0c08174] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
The effects of alkaline-earth metal cation (AMC; Mg2+, Ca2+, Sr2+, and Ba2+) substitution on the photoelectrochemical properties of phase-pure LaFeO3 (LFO) thin-films are elucidated by X-ray photoemission spectroscopy (XPS), X-ray diffraction (XRD), diffuse reflectance, and electrochemical impedance spectroscopy (EIS). XRD confirms the formation of single-phase cubic LFO thin films with a rather complex dependence on the nature of the AMC and extent of substitution. Interestingly, subtle trends in lattice constant variations observed in XRD are closely correlated with shifts in the binding energies of Fe 2p3/2 and O 1s orbitals associated with the perovskite lattice. We establish a scaling factor between these two photoemission peaks, unveiling key correlation between Fe oxidation state and Fe-O covalency. Diffuse reflectance shows that optical transitions are little affected by AMC substitution below 10%, which are dominated by a direct bandgap transition close to 2.72 eV. Differential capacitance data obtained from EIS confirm the p-type characteristic of pristine LFO thin-films, revealing the presence of sub-bandgap electronic state (A-states) close to the valence band edge. The density of A-states is decreased upon AMC substitution, while the overall capacitance increases (increase in dopant level) and the apparent flat-band potential shifts toward more positive potentials. This behavior is consistent with the change in the valence band photoemission edge. In addition, capacitance data of cation-substituted films show the emergence of deeper states centered around 0.6 eV above the valence band edge (B-states). Photoelectrochemical responses toward the hydrogen evolution and oxygen reduction reactions in alkaline solutions show a complex dependence on alkaline-earth metal incorporation, reaching incident-photon-to-current conversion efficiency close to 20% in oxygen saturated solutions. We rationalize the photoresponses of the LFO films in terms of the effect sub-bandgap states on majority carrier mobility, charge transfer, and recombination kinetics.
Collapse
Affiliation(s)
- Xin Sun
- School of Chemistry, University of Bristol, Cantocks Close, Bristol BS8 1TS, U.K
| | - Devendra Tiwari
- School of Chemistry, University of Bristol, Cantocks Close, Bristol BS8 1TS, U.K
| | - David J Fermin
- School of Chemistry, University of Bristol, Cantocks Close, Bristol BS8 1TS, U.K
| |
Collapse
|
8
|
Son MK, Seo H, Watanabe M, Shiratani M, Ishihara T. Characteristics of crystalline sputtered LaFeO 3 thin films as photoelectrochemical water splitting photocathodes. NANOSCALE 2020; 12:9653-9660. [PMID: 32319489 DOI: 10.1039/d0nr01762k] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
Stable photoelectrochemical (PEC) operation is a critical issue for the commercialization of PEC water-splitting systems. Unfortunately, most semiconductor photocathodes generating hydrogen in these systems are unstable in aqueous solutions. This is a huge limitation for the development of durable PEC water-splitting systems. Lanthanum iron oxide (LaFeO3) is a promising p-type semiconductor to overcome this drawback because of its stability in an aqueous solution and its proper energy level for reducing water. In this study, we fabricated a crystalline LaFeO3 thin film by radio frequency magnetron sputtering deposition and a post-annealing process in air for use as a PEC photocathode. Based on the morphological, compositional, optical and electronic characterizations, we found that it was ideal for a visible light-responsive PEC photocathode and tandem PEC water-splitting system with a small band gap absorber behind it. Furthermore, it showed stable PEC performance in a strong alkaline solution during PEC operation without any protection layers. Therefore, the crystalline sputtered LaFeO3 thin film suggested in this study would be feasible to apply as a PEC photocathode for durable, simple and low-cost PEC water splitting.
Collapse
Affiliation(s)
- Min-Kyu Son
- Molecular Photoconversion Devices Research Division, International Institute for Carbon-Neutral Energy Research(I2CNER), Kyushu University, 744 Motooka, Nishi-ku, Fukuoka 819-0395, Japan. and Center of Plasma Nano-interface Engineering, Kyushu University, 744 Motooka, Nishi-ku, Fukuoka 819-0395, Japan
| | - Hyunwoong Seo
- Department of Energy Engineering, Inje University, 197 Inje-ro, Gimhae-si, Gyeongsangnam-do 50834, Republic of Korea
| | - Motonori Watanabe
- Molecular Photoconversion Devices Research Division, International Institute for Carbon-Neutral Energy Research(I2CNER), Kyushu University, 744 Motooka, Nishi-ku, Fukuoka 819-0395, Japan.
| | - Masaharu Shiratani
- Center of Plasma Nano-interface Engineering, Kyushu University, 744 Motooka, Nishi-ku, Fukuoka 819-0395, Japan and Faculty of Information Science and Electrical Engineering, Kyushu University, 744 Motooka, Nishi-ku, Fukuoka 819-0395, Japan
| | - Tatsumi Ishihara
- Molecular Photoconversion Devices Research Division, International Institute for Carbon-Neutral Energy Research(I2CNER), Kyushu University, 744 Motooka, Nishi-ku, Fukuoka 819-0395, Japan.
| |
Collapse
|
9
|
Monllor-Satoca D, Díez-García MI, Lana-Villarreal T, Gómez R. Photoelectrocatalytic production of solar fuels with semiconductor oxides: materials, activity and modeling. Chem Commun (Camb) 2020; 56:12272-12289. [DOI: 10.1039/d0cc04387g] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Transition metal oxides keep on being excellent candidates as electrode materials for the photoelectrochemical conversion of solar energy into chemical energy.
Collapse
Affiliation(s)
- Damián Monllor-Satoca
- Departament de Química Física i Institut Universitari d'Electroquímica
- Universitat d'Alacant
- Alicante
- Spain
| | - María Isabel Díez-García
- Departament de Química Física i Institut Universitari d'Electroquímica
- Universitat d'Alacant
- Alicante
- Spain
| | - Teresa Lana-Villarreal
- Departament de Química Física i Institut Universitari d'Electroquímica
- Universitat d'Alacant
- Alicante
- Spain
| | - Roberto Gómez
- Departament de Química Física i Institut Universitari d'Electroquímica
- Universitat d'Alacant
- Alicante
- Spain
| |
Collapse
|
10
|
Lumley MA, Radmilovic A, Jang YJ, Lindberg AE, Choi KS. Perspectives on the Development of Oxide-Based Photocathodes for Solar Fuel Production. J Am Chem Soc 2019; 141:18358-18369. [PMID: 31693356 DOI: 10.1021/jacs.9b07976] [Citation(s) in RCA: 51] [Impact Index Per Article: 10.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Photoelectrochemical cells (PECs), which use semiconductor electrodes (photoelectrodes) to absorb solar energy and perform chemical reactions, constitute one of the most attractive strategies to produce chemical fuels using renewable energy sources. Oxide-based photoelectrodes specifically have been intensively investigated for the construction of PECs due to their relatively inexpensive processing costs and better stability in aqueous media compared with other types of photoelectrodes. Although there have been many advancements in the development of oxide-based photoanodes, our understanding of oxide-based photocathodes remains limited. The goal of this Perspective is to examine the recent progress made in the field of oxide-based photocathodes and discuss future research directions. The photocathode systems considered here include binary and ternary Cu-based photocathodes and ternary Fe-based photocathodes. We assessed the characteristics and major advantages and drawbacks of each system and identified the most critical research gaps. The insights and discussions provided in this Perspective will serve as useful resources for the design of future studies, leading to the development of more efficient and practical PECs.
Collapse
Affiliation(s)
- Margaret A Lumley
- Department of Chemistry , University of Wisconsin-Madison , Madison , Wisconsin 53706 , United States
| | - Andjela Radmilovic
- Department of Chemistry , University of Wisconsin-Madison , Madison , Wisconsin 53706 , United States
| | - Youn Jeong Jang
- Department of Chemistry , University of Wisconsin-Madison , Madison , Wisconsin 53706 , United States
| | - Ann E Lindberg
- Department of Chemistry , University of Wisconsin-Madison , Madison , Wisconsin 53706 , United States
| | - Kyoung-Shin Choi
- Department of Chemistry , University of Wisconsin-Madison , Madison , Wisconsin 53706 , United States
| |
Collapse
|
11
|
Plasmon-enhanced hierarchical photoelectrodes with mechanical flexibility for hydrogen generation from urea solution and human urine. J APPL ELECTROCHEM 2019. [DOI: 10.1007/s10800-019-01369-0] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
|
12
|
Heifets E, Kotomin EA, Bagaturyants AA, Maier J. Thermodynamic stability of non-stoichiometric SrFeO 3-δ: a hybrid DFT study. Phys Chem Chem Phys 2019; 21:3918-3931. [PMID: 30702110 DOI: 10.1039/c8cp07117a] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
SrFeO3-δ is a mixed ionic-electronic conductor with a complex magnetic structure that reveals a colossal magnetoresistance effect. This material and its solid solutions are attractive for various spintronic, catalytic and electrochemical applications, including cathodes for solid oxide fuel cells and permeation membranes. Its properties strongly depend on oxygen non-stoichiometry. Ab initio hybrid functional approach was applied herein to study the thermodynamic stability of a series of SrFeO3-δ compositions with several non-stoichiometries δ, ranging from 0 to 0.5 (SrFeO3-SrFeO2.875-SrFeO2.75-SrFeO2.5) as a function of temperature and oxygen pressure. The results obtained by two approaches, in which either (i) all electrons at Fe atoms explicitly described or (ii) inner core electrons at Fe atoms are replaced by effective core potential, are compared. Based on our calculations, phase diagrams were constructed, allowing the determination of environmental conditions for the existence of stable phases. It is shown that (within an employed model) only the SrFeO2.5 phase appears to be stable. The stability region for this phase was re-drawn on the contour map of oxygen chemical potential, presented as a function of temperature and oxygen partial pressure. A similar analysis was also performed using experimental Gibbs energies of perovskite formation from the elements. The present modelling strongly suggest a significant attraction between neutral oxygen vacancies. These vacancies are created during a series of the abovementioned SrFeO3-δ mutual transformations accompanied by oxygen release.
Collapse
Affiliation(s)
- Eugene Heifets
- Photochemistry Center, Federal Research Center "Crystallography and Photonics", Russian Academy of Sciences, Novatorov 7a, Moscow, 119421, Russia.
| | | | | | | |
Collapse
|
13
|
Ferroelectric Materials: A Novel Pathway for Efficient Solar Water Splitting. APPLIED SCIENCES-BASEL 2018. [DOI: 10.3390/app8091526] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
Abstract
Over the past few decades, solar water splitting has evolved into one of the most promising techniques for harvesting hydrogen using solar energy. Despite the high potential of this process for hydrogen production, many research groups have encountered significant challenges in the quest to achieve a high solar-to-hydrogen conversion efficiency. Recently, ferroelectric materials have attracted much attention as promising candidate materials for water splitting. These materials are among the best candidates for achieving water oxidation using solar energy. Moreover, their characteristics are changeable by atom substitute doping or the fabrication of a new complex structure. In this review, we describe solar water splitting technology via the solar-to-hydrogen conversion process. We will examine the challenges associated with this technology whereby ferroelectric materials are exploited to achieve a high solar-to-hydrogen conversion efficiency.
Collapse
|
14
|
Photoelectrochemical Response of WO3/Nanoporous Carbon Anodes for Photocatalytic Water Oxidation. C — JOURNAL OF CARBON RESEARCH 2018. [DOI: 10.3390/c4030045] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
This work demonstrates the ability of nanoporous carbons to boost the photoelectrochemical activity of hexagonal and monoclinic WO3 towards water oxidation under irradiation. The impact of the carbonaceous phase was strongly dependent on the crystalline structure and morphology of the semiconductor, substantially increasing the activity of WO3 rods with hexagonal phase. The incorporation of increasing amounts of a nanoporous carbon of low functionalization to the WO3 electrodes improved the quantum yield of the reaction and also affected the dynamics of the charge transport, creating a percolation path for the majority carriers. The nanoporous carbon promotes the delocalization of the charge carriers through the graphitic layers. We discuss the incorporation of nanoporous carbons as an interesting strategy for improving the photoelectrochemical performance of nanostructured semiconductor photoelectrodes featuring hindered carrier transport.
Collapse
|
15
|
Gobaille‐Shaw GPA, Celorrio V, Calvillo L, Morris LJ, Granozzi G, Fermín DJ. Effect of Ba Content on the Activity of La 1-x Ba x MnO 3 Towards the Oxygen Reduction Reaction. ChemElectroChem 2018; 5:1922-1927. [PMID: 30263882 PMCID: PMC6146913 DOI: 10.1002/celc.201800052] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2018] [Indexed: 01/01/2023]
Abstract
The electrocatalytic activity of La1-x Ba x MnO3 nanoparticles towards the oxygen reduction reaction (ORR) is investigated as a function of the A-site composition. Phase-pure oxide nanoparticles with a diameter in the range of 40 to 70 nm were prepared by using an ionic liquid route and deposited onto mesoporous carbon films. The structure and surface composition of the nanoparticles are probed by XRD, TEM, EDX, and XPS. Electrochemical studies carried out under alkaline conditions show a strong correlation between the activity of La1-x Ba x MnO3 and the effective number of reducible Mn sites at the catalysts layer. Our analysis demonstrates that, beyond controlling particle size and surface elemental segregation, understanding and controlling Mn coordination at the first atomic layer is crucial for increasing the performance of these materials.
Collapse
Affiliation(s)
- Gael. P. A. Gobaille‐Shaw
- School of ChemistryUniversity of Bristol Cantocks CloseBristolBS8 1TSUK
- EPSRC Centre for Doctoral Training in Catalysis School of ChemistryCardiff University Main BuildingPark PlaceCardiffCF10 3ATUK
| | - Veronica Celorrio
- School of ChemistryUniversity of Bristol Cantocks CloseBristolBS8 1TSUK
- UK Catalysis Hub, Research Complex at Harwell RAL, Oxford, OX11 0FA, UK and Kathleen Lonsdale Building Department of ChemistryUniversity College LondonGordon StreetLondonWC1H 0AJUK
| | - Laura Calvillo
- Dipartimento di Scienze ChimicheUniversità di PadovaVia Marzolo 135131PadovaItaly
| | - Louis J. Morris
- EPSRC Centre for Doctoral Training in Catalysis School of ChemistryCardiff University Main BuildingPark PlaceCardiffCF10 3ATUK
| | - Gaetano Granozzi
- Dipartimento di Scienze ChimicheUniversità di PadovaVia Marzolo 135131PadovaItaly
| | - David. J. Fermín
- School of ChemistryUniversity of Bristol Cantocks CloseBristolBS8 1TSUK
| |
Collapse
|
16
|
Stephenson J, Celorrio V, Tiwari D, Hall SR, Green DC, Fermín DJ. Photoelectrochemical properties of BiOCl microplatelets. J Electroanal Chem (Lausanne) 2018. [DOI: 10.1016/j.jelechem.2017.10.024] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
|
17
|
Nassar IM, Wu S, Li L, Li X. Facile Preparation ofn‐Type LaFeO3Perovskite Film for Efficient Photoelectrochemical Water Splitting. ChemistrySelect 2018. [DOI: 10.1002/slct.201702997] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Affiliation(s)
- Ibrahim M. Nassar
- Colleges of PhysicsOptoelectronics and Energy & Collaborative InnovationCenter of Suzhou Nano Science and TechnologySoochow University Suzhou 215006 China
- Egyptian Petroleum Research Institute (EPRI) Ahmed El-Zomor St., Nasr City 11727 Cairo Egypt
| | - Shaolong Wu
- Colleges of PhysicsOptoelectronics and Energy & Collaborative InnovationCenter of Suzhou Nano Science and TechnologySoochow University Suzhou 215006 China
| | - Liang Li
- Colleges of PhysicsOptoelectronics and Energy & Collaborative InnovationCenter of Suzhou Nano Science and TechnologySoochow University Suzhou 215006 China
| | - Xiaofeng Li
- Colleges of PhysicsOptoelectronics and Energy & Collaborative InnovationCenter of Suzhou Nano Science and TechnologySoochow University Suzhou 215006 China
| |
Collapse
|
18
|
Celorrio V, Calvillo L, Granozzi G, Russell AE, Fermin DJ. AMnO 3 (A = Sr, La, Ca, Y) Perovskite Oxides as Oxygen Reduction Electrocatalysts. Top Catal 2018; 61:154-161. [PMID: 30956502 PMCID: PMC6413806 DOI: 10.1007/s11244-018-0886-5] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
A series of perovskite-type manganites AMnO3 (A = Sr, La, Ca and Y) particles were investigated as electrocatalysts for the oxygen reduction reaction. AMnO3 materials were synthesized by means of an ionic-liquid method, yielding phase pure particles at different temperatures. Depending on the calcination temperature, particles with mean diameter between 20 and 150 nm were obtained. Bulk versus surface composition and structure are probed by X-ray photoelectron spectroscopy and extended X-ray absorption fine structure. Electrochemical studies were performed on composite carbon-oxide electrodes in alkaline environment. The electrocatalytic activity is discussed in terms of the effective Mn oxidation state, A:Mn particle surface ratio and the Mn-O distances.
Collapse
Affiliation(s)
- V. Celorrio
- School of Chemistry, University of Bristol, Cantocks Close, Bristol, BS8 1TS UK
| | - L. Calvillo
- Dipartimento di Scienze Chimiche, Università di Padova, Via Marzolo 1, 35131 Padua, Italy
| | - G. Granozzi
- Dipartimento di Scienze Chimiche, Università di Padova, Via Marzolo 1, 35131 Padua, Italy
| | - A. E. Russell
- School of Chemistry, University of Southampton, Highfield, Southampton, UK
| | - D. J. Fermin
- School of Chemistry, University of Bristol, Cantocks Close, Bristol, BS8 1TS UK
| |
Collapse
|
19
|
|
20
|
Díez-García MI, Gómez R. Metal Doping to Enhance the Photoelectrochemical Behavior of LaFeO 3 Photocathodes. CHEMSUSCHEM 2017; 10:2457-2463. [PMID: 28317341 DOI: 10.1002/cssc.201700166] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/30/2017] [Revised: 03/16/2017] [Indexed: 06/06/2023]
Abstract
The development of tandem devices for water photosplitting requires the preparation of photocathodic materials based on earth-abundant elements that show long-term stability in aqueous electrolytes. Ternary metal oxides seem to be a viable option, among which perovskites stand out. In this context, transparent and compact LaFeO3 thin-film electrodes have been prepared by a sol-gel process, both undoped and doped with metals (M) such as Mg or Zn. Pristine electrodes support the development of cathodic photocurrents in 0.1 m NaOH aqueous solutions, particularly in the presence of oxygen, with an onset potential as high as 1.4 V versus the reversible hydrogen electrode. Doping with Mg or Zn leads to an important enhancement of the photocurrent, which peaks for a stoichiometry of LaFe0.95 M0.05 O3 with a sixfold enhancement with respect to the pristine material. Such an improvement is attributed to an increase in both the density and mobility of the majority carriers, although a contribution of surface passivation cannot be excluded.
Collapse
Affiliation(s)
- María Isabel Díez-García
- Departament de Química Física i Institut Universitari d'Electroquímica, Universitat d'Alacant, Apartat 99, E-, 03080, Alicante, Spain
| | - Roberto Gómez
- Departament de Química Física i Institut Universitari d'Electroquímica, Universitat d'Alacant, Apartat 99, E-, 03080, Alicante, Spain
| |
Collapse
|
21
|
Díez-García MI, Gómez R. Investigating Water Splitting with CaFe2O4 Photocathodes by Electrochemical Impedance Spectroscopy. ACS APPLIED MATERIALS & INTERFACES 2016; 8:21387-21397. [PMID: 27466695 DOI: 10.1021/acsami.6b07465] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
Artificial photosynthesis constitutes one of the most promising alternatives for harvesting solar energy in the form of fuels, such as hydrogen. Among the different devices that could be developed to achieve efficient water photosplitting, tandem photoelectrochemical cells show more flexibility and offer high theoretical conversion efficiency. The development of these cells depends on finding efficient and stable photoanodes and, particularly, photocathodes, which requires having reliable information on the mechanism of charge transfer at the semiconductor/solution interface. In this context, this work deals with the preparation of thin film calcium ferrite electrodes and their photoelectrochemical characterization for hydrogen generation by means of electrochemical impedance spectroscopy (EIS). A fully theoretical model that includes elementary steps for electron transfer to the electrolyte and surface recombination with photogenerated holes is presented. The model also takes into account the complexity of the semiconductor/solution interface by including the capacitances of the space charge region, the surface states and the Helmholtz layer (as a constant phase element). After illustrating the predicted Nyquist plots in a general manner, the experimental results for calcium ferrite electrodes at different applied potentials and under different illumination intensities are fitted to the model. The excellent agreement between the model and the experimental results is illustrated by the simultaneous fit of both Nyquist and Bode plots. The concordance between both theory and experiments allows us to conclude that a direct transfer of electrons from the conduction band to water prevails for hydrogen photogeneration on calcium ferrite electrodes and that most of the carrier recombination occurs in the material bulk. In more general vein, this study illustrates how the use of EIS may provide important clues about the behavior of photoelectrodes and the main strategies for their improvement.
Collapse
Affiliation(s)
- María Isabel Díez-García
- Departament de Química Física i Institut Universitari d'Electroquímica, Universitat d'Alacant , Apartat 99, E-03080 Alacant, Spain
| | - Roberto Gómez
- Departament de Química Física i Institut Universitari d'Electroquímica, Universitat d'Alacant , Apartat 99, E-03080 Alacant, Spain
| |
Collapse
|
22
|
Díez-García MI, Lana-Villarreal T, Gómez R. Study of Copper Ferrite as a Novel Photocathode for Water Reduction: Improving Its Photoactivity by Electrochemical Pretreatment. CHEMSUSCHEM 2016; 9:1504-1512. [PMID: 27161046 DOI: 10.1002/cssc.201600023] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/06/2016] [Revised: 02/29/2016] [Indexed: 06/05/2023]
Abstract
Studies on water-splitting p-type oxide electrodes based on nontoxic earth-abundant elements are scarce. Herein, the behavior of electrodes composed of CuFe2 O4 nanoparticles 30 nm in size is presented. The as-prepared CuFe2 O4 nanoporous electrodes exhibit small anodic photocurrents in 0.1 m NaOH. However, an electrochemical pretreatment consisting in the application of sufficiently positive potentials leads to p-type behavior with a photocurrent onset as high as 1.1 V versus the reversible hydrogen electrode, which is among the most positive values reported for an oxide absorbing visible light (band gap of 2.1 eV). This photocurrent is partly due to H2 evolution, but there are also signs of photoreduction of the material. Although the photocurrents are modest, these results point to the possibility of using CuFe2 O4 as a photocathode material in water-splitting devices. Furthermore, the strategy employed for the enhancement in the CuFe2 O4 photoactivity could be extended to other photocathode materials.
Collapse
Affiliation(s)
- María Isabel Díez-García
- Departament de Química Física i Institut Universitari d'Electroquímica, Universitat d'Alacant, Apartat 99, E-03080, Alacant, Spain
| | - Teresa Lana-Villarreal
- Departament de Química Física i Institut Universitari d'Electroquímica, Universitat d'Alacant, Apartat 99, E-03080, Alacant, Spain.
| | - Roberto Gómez
- Departament de Química Física i Institut Universitari d'Electroquímica, Universitat d'Alacant, Apartat 99, E-03080, Alacant, Spain.
| |
Collapse
|
23
|
Peng Q, Wang J, Wen YW, Shan B, Chen R. Surface modification of LaFeO3 by Co-Pi electrochemical deposition as an efficient photoanode under visible light. RSC Adv 2016. [DOI: 10.1039/c6ra01810f] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
The PEC performance of LaFeO3 is promoted by Co-Pi coating due to improved surface catalytic activity and enhanced carrier separation.
Collapse
Affiliation(s)
- Q. Peng
- State Key Laboratory of Digital Manufacturing Equipment and Technology
- School of Mechanical Science and Engineering
- Huazhong University of Science and Technology
- Wuhan 430074
- People's Republic of China
| | - J. Wang
- State Key Laboratory of Materials Processing and Die & Mould Technology
- School of Materials Science and Engineering
- Huazhong University of Science and Technology
- Wuhan 430074
- People's Republic of China
| | - Y. W. Wen
- State Key Laboratory of Materials Processing and Die & Mould Technology
- School of Materials Science and Engineering
- Huazhong University of Science and Technology
- Wuhan 430074
- People's Republic of China
| | - B. Shan
- State Key Laboratory of Materials Processing and Die & Mould Technology
- School of Materials Science and Engineering
- Huazhong University of Science and Technology
- Wuhan 430074
- People's Republic of China
| | - R. Chen
- State Key Laboratory of Digital Manufacturing Equipment and Technology
- School of Mechanical Science and Engineering
- Huazhong University of Science and Technology
- Wuhan 430074
- People's Republic of China
| |
Collapse
|
24
|
Celorrio V, Calvillo L, Dann E, Granozzi G, Aguadero A, Kramer D, Russell AE, Fermín DJ. Oxygen reduction reaction at LaxCa1−xMnO3 nanostructures: interplay between A-site segregation and B-site valency. Catal Sci Technol 2016. [DOI: 10.1039/c6cy01105e] [Citation(s) in RCA: 57] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Detailed surface vs. bulk composition studies of LaxCa1−xMnO3 oxides provide clear evidence that the ORR activity increases as the effective electron population at the Mn site increases.
Collapse
Affiliation(s)
| | - Laura Calvillo
- Dipartimento di Scienze Chimiche
- Università di Padova
- 35131 Padova
- Italy
| | - Ellie Dann
- School of Chemistry
- University of Bristol
- Bristol
- UK
| | - Gaetano Granozzi
- Dipartimento di Scienze Chimiche
- Università di Padova
- 35131 Padova
- Italy
| | | | - Denis Kramer
- Engineering Sciences
- University of Southampton
- Southampton
- UK
| | | | | |
Collapse
|
25
|
Celorrio V, Dann E, Calvillo L, Morgan DJ, Hall SR, Fermin DJ. Oxygen Reduction at Carbon-Supported Lanthanides: The Role of the B-Site. ChemElectroChem 2015. [DOI: 10.1002/celc.201500440] [Citation(s) in RCA: 55] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Affiliation(s)
- Verónica Celorrio
- School of Chemistry; University of Bristol, Cantocks Close; Bristol BS8 1TS UK
| | - Ellie Dann
- School of Chemistry; University of Bristol, Cantocks Close; Bristol BS8 1TS UK
| | - Laura Calvillo
- Dipartimento di Scienze Chimiche; Università di Padova; Via Marzolo 1 35131 Padova Italy
| | - David J. Morgan
- Cardiff Catalysis Institute; School of Chemistry; Cardiff University; Cardiff CF10 3AT UK
| | - Simon R. Hall
- School of Chemistry; University of Bristol, Cantocks Close; Bristol BS8 1TS UK
| | - David J. Fermin
- School of Chemistry; University of Bristol, Cantocks Close; Bristol BS8 1TS UK
| |
Collapse
|
26
|
Yu Q, Meng X, Wang T, Li P, Liu L, Chang K, Liu G, Ye J. A highly durable p-LaFeO3/n-Fe2O3 photocell for effective water splitting under visible light. Chem Commun (Camb) 2015; 51:3630-3. [DOI: 10.1039/c4cc09240f] [Citation(s) in RCA: 72] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
A new p-type photocathode LaFeO3 was successfully fabricated, and a stable (120 h) and effective water splitting (H2: 11.5 μmol h−1, O2: 5.7 μmol h−1) was realized via construction of a p-LaFeO3/n-Fe2O3 photocell.
Collapse
Affiliation(s)
- Qing Yu
- Graduate School of Chemical Science and Engineering
- Hokkaido University
- Sapporo
- Japan
- International Center for Materials Nanoarchitectonics (WPI-MANA)
| | - Xianguang Meng
- Graduate School of Chemical Science and Engineering
- Hokkaido University
- Sapporo
- Japan
- International Center for Materials Nanoarchitectonics (WPI-MANA)
| | - Tao Wang
- International Center for Materials Nanoarchitectonics (WPI-MANA)
- and Environmental Remediation Materials Unit
- National Institute for Materials Science (NIMS)
- Tsukuba
- Japan
| | - Peng Li
- International Center for Materials Nanoarchitectonics (WPI-MANA)
- and Environmental Remediation Materials Unit
- National Institute for Materials Science (NIMS)
- Tsukuba
- Japan
| | - Lequan Liu
- International Center for Materials Nanoarchitectonics (WPI-MANA)
- and Environmental Remediation Materials Unit
- National Institute for Materials Science (NIMS)
- Tsukuba
- Japan
| | - Kun Chang
- International Center for Materials Nanoarchitectonics (WPI-MANA)
- and Environmental Remediation Materials Unit
- National Institute for Materials Science (NIMS)
- Tsukuba
- Japan
| | - Guigao Liu
- Graduate School of Chemical Science and Engineering
- Hokkaido University
- Sapporo
- Japan
- International Center for Materials Nanoarchitectonics (WPI-MANA)
| | - Jinhua Ye
- Graduate School of Chemical Science and Engineering
- Hokkaido University
- Sapporo
- Japan
- International Center for Materials Nanoarchitectonics (WPI-MANA)
| |
Collapse
|