1
|
Yuan X, Ge W, Zhu Y, Dong L, Jiang H, Li C. Anionic Surfactant-Tailored Interfacial Microenvironment for Boosting Electrochemical CO 2 Reduction. ACS APPLIED MATERIALS & INTERFACES 2024; 16:38083-38091. [PMID: 38986045 DOI: 10.1021/acsami.4c07258] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 07/12/2024]
Abstract
Both the catalyst and electrolyte deeply impact the performance of the carbon dioxide reduction reaction (CO2RR). It remains a challenge to design the electrolyte compositions for promoting the CO2RR. Here, typical anionic surfactants, dodecylphosphonic acid (DDPA) and its analogues, are employed as electrolyte additives to tune the catalysis interface where the CO2RR occurs. Surprisingly, the anionic surfactant-tailored interfacial microenvironment enables a set of typical commercial catalysts for the CO2RR to deliver a significantly enhanced selectivity of carbon products in both neutral and acidic electrolytes. Mechanistic studies disclose that the DDPA addition restructures the interfacial hydrogen-bond environment via increasing the weak H-bonded water, thus promoting the CO2 protonation to CO. Specifically, in an H-type cell, the Faradaic efficiency of CO increases from 70 to 98% at -1.0 V versus the reversible hydrogen electrode. Furthermore, in a flow cell, the DDPA-containing electrolyte maintains over 90% FECO from 50-400 mA cm-2. Additionally, this electrolyte modulation strategy can be extended to acidic CO2RR with a pH of 1.5-3.5.
Collapse
Affiliation(s)
- Xin Yuan
- Key Laboratory for Ultrafine Materials of Ministry of Education, School of Chemical Engineering, East China University of Science and Technology, Shanghai 200237, China
- Shanghai Engineering Research Center of Hierarchical Nanomaterials, School of Materials Science and Engineering, East China University of Science and Technology, Shanghai 200237, China
| | - Wangxin Ge
- Key Laboratory for Ultrafine Materials of Ministry of Education, School of Chemical Engineering, East China University of Science and Technology, Shanghai 200237, China
- Shanghai Engineering Research Center of Hierarchical Nanomaterials, School of Materials Science and Engineering, East China University of Science and Technology, Shanghai 200237, China
| | - Yihua Zhu
- Shanghai Engineering Research Center of Hierarchical Nanomaterials, School of Materials Science and Engineering, East China University of Science and Technology, Shanghai 200237, China
| | - Lei Dong
- Key Laboratory for Ultrafine Materials of Ministry of Education, School of Chemical Engineering, East China University of Science and Technology, Shanghai 200237, China
| | - Hongliang Jiang
- Key Laboratory for Ultrafine Materials of Ministry of Education, School of Chemical Engineering, East China University of Science and Technology, Shanghai 200237, China
| | - Chunzhong Li
- Key Laboratory for Ultrafine Materials of Ministry of Education, School of Chemical Engineering, East China University of Science and Technology, Shanghai 200237, China
- Shanghai Engineering Research Center of Hierarchical Nanomaterials, School of Materials Science and Engineering, East China University of Science and Technology, Shanghai 200237, China
| |
Collapse
|
2
|
Jones TE, Teschner D, Piccinin S. Toward Realistic Models of the Electrocatalytic Oxygen Evolution Reaction. Chem Rev 2024. [PMID: 39038270 DOI: 10.1021/acs.chemrev.4c00171] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 07/24/2024]
Abstract
The electrocatalytic oxygen evolution reaction (OER) supplies the protons and electrons needed to transform renewable electricity into chemicals and fuels. However, the OER is kinetically sluggish; it operates at significant rates only when the applied potential far exceeds the reversible voltage. The origin of this overpotential is hidden in a complex mechanism involving multiple electron transfers and chemical bond making/breaking steps. Our desire to improve catalytic performance has then made mechanistic studies of the OER an area of major scientific inquiry, though the complexity of the reaction has made understanding difficult. While historically, mechanistic studies have relied solely on experiment and phenomenological models, over the past twenty years ab initio simulation has been playing an increasingly important role in developing our understanding of the electrocatalytic OER and its reaction mechanisms. In this Review we cover advances in our mechanistic understanding of the OER, organized by increasing complexity in the way through which the OER is modeled. We begin with phenomenological models built using experimental data before reviewing early efforts to incorporate ab initio methods into mechanistic studies. We go on to cover how the assumptions in these early ab initio simulations─no electric field, electrolyte, or explicit kinetics─have been relaxed. Through comparison with experimental literature, we explore the veracity of these different assumptions. We summarize by discussing the most critical open challenges in developing models to understand the mechanisms of the OER.
Collapse
Affiliation(s)
- Travis E Jones
- Theoretical Division, Los Alamos National Laboratory, Los Alamos, New Mexico 87545, United States
- Department of Inorganic Chemistry, Fritz-Haber-Institute of the Max-Planck-Society, Berlin 14195, Germany
| | - Detre Teschner
- Department of Inorganic Chemistry, Fritz-Haber-Institute of the Max-Planck-Society, Berlin 14195, Germany
- Department of Heterogeneous Reactions, Max-Planck-Institute for Chemical Energy Conversion, Mülheim an der Ruhr 45470, Germany
| | - Simone Piccinin
- Consiglio Nazionale delle Ricerche, Istituto Officina dei Materiali, Trieste 34136, Italy
| |
Collapse
|
3
|
Zhang WY, Ma XY, Jiang TW, Xu X, Ni B, Chen B, Wang Y, Jiang K, Cai WB. Atomic Layer Deposition of TiO 2 on Si Window Enables In Situ ATR-SEIRAS Measurements in Strong Alkaline Electrolytes. Anal Chem 2024; 96:10111-10115. [PMID: 38869290 DOI: 10.1021/acs.analchem.4c01985] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/14/2024]
Abstract
The Si window is the most widely used internal reflection element (IRE) for electrochemical attenuated total reflection surface-enhanced infrared absorption spectroscopy (ATR-SEIRAS), yet local chemical etching on Si by concentrated OH- anions bottlenecks the reliable application of this method in strong alkaline electrolytes. In this report, atomic layer deposition of a 25 nm nonconductive TiO2 barrier layer on the reflecting plane of a Si prism is demonstrated to address this challenge. In situ ATR-SEIRAS measurement on a Au film electrode with the Si/TiO2 composite IRE in 1 M NaOH reveals reversible global spectral features without spectral distortion at 1000-1300 cm-1, in stark contrast to those obtained with a bare Si window. By applying this structured ATR-SEIRAS, ethanol electrooxidation on a Pt/C catalyst in 1 and 5 M NaOH is explored, manifesting that such high pH values prevent the adsorption of as-formed acetate in the C2 pathway but not that of CO intermediate in the C1 pathway.
Collapse
Affiliation(s)
- Wei-Yi Zhang
- Shanghai Key Laboratory of Molecular Catalysis and Innovative Materials, Collaborative Innovation Center of Chemistry for Energy Materials, Department of Chemistry, Fudan University, Shanghai 200438, China
| | - Xian-Yin Ma
- Shanghai Key Laboratory of Molecular Catalysis and Innovative Materials, Collaborative Innovation Center of Chemistry for Energy Materials, Department of Chemistry, Fudan University, Shanghai 200438, China
| | - Tian-Wen Jiang
- Shanghai Key Laboratory of Molecular Catalysis and Innovative Materials, Collaborative Innovation Center of Chemistry for Energy Materials, Department of Chemistry, Fudan University, Shanghai 200438, China
| | - Xindi Xu
- Shanghai Key Laboratory of Molecular Catalysis and Innovative Materials, Collaborative Innovation Center of Chemistry for Energy Materials, Department of Chemistry, Fudan University, Shanghai 200438, China
| | - Baoxin Ni
- Interdisciplinary Research Center, School of Mechanical Engineering, Shanghai Jiao Tong University, Shanghai 200240, China
| | - Bin Chen
- YUNMAO Technology Co., Ltd, Xiamen 361000, China
| | - Yunyu Wang
- YUNMAO Technology Co., Ltd, Xiamen 361000, China
| | - Kun Jiang
- Shanghai Key Laboratory of Molecular Catalysis and Innovative Materials, Collaborative Innovation Center of Chemistry for Energy Materials, Department of Chemistry, Fudan University, Shanghai 200438, China
- Interdisciplinary Research Center, School of Mechanical Engineering, Shanghai Jiao Tong University, Shanghai 200240, China
| | - Wen-Bin Cai
- Shanghai Key Laboratory of Molecular Catalysis and Innovative Materials, Collaborative Innovation Center of Chemistry for Energy Materials, Department of Chemistry, Fudan University, Shanghai 200438, China
| |
Collapse
|
4
|
Zhou Y, Gao J, Ju M, Chen Y, Yuan H, Li S, Li J, Guo D, Hong M, Yang S. Combustion Growth of NiFe Layered Double Hydroxide for Efficient and Durable Oxygen Evolution Reaction. ACS APPLIED MATERIALS & INTERFACES 2024; 16:28526-28536. [PMID: 38775170 DOI: 10.1021/acsami.4c03766] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2024]
Abstract
NiFe layered double hydroxide (LDH) with abundant heterostructures represents a state-of-the-art electrocatalyst for the alkaline oxygen evolution reaction (OER). Herein, NiFe LDH/Fe2O3 nanosheet arrays have been fabricated by facile combustion of corrosion-engineered NiFe foam (NFF). The in situ grown, self-supported electrocatalyst exhibited a low overpotential of 248 mV for the OER at 50 mA cm-2, a small Tafel slope of 31 mV dec-1, and excellent durability over 100 h under the industrial benchmarking 500 mA cm-2 current density. A balanced Ni and Fe composition under optimal corrosion and combustion contributed to the desirable electrochemical properties. Comprehensive ex-situ analyses and operando characterizations including Fourier-transformed alternating current voltammetry (FTACV) and in situ Raman demonstrate the beneficial role of modulated interfacial electron transfer, dynamic atomic structural transformation to NiOOH, and the high-valence active metal sites. This study provides a low-cost and easy-to-expand way to synthesize efficient and durable electrocatalysts.
Collapse
Affiliation(s)
- Yu Zhou
- College of Chemistry and Chemical Engineering, Qiqihar University, Qiqihar 161006, China
| | - Jinqiang Gao
- Guangdong Provincial Key Laboratory of Nano-Micro Materials Research, School of Advanced Materials, Peking University Shenzhen Graduate School, Shenzhen 518055, China
| | - Min Ju
- Guangdong Provincial Key Laboratory of Nano-Micro Materials Research, School of Advanced Materials, Peking University Shenzhen Graduate School, Shenzhen 518055, China
| | - Yanpeng Chen
- State Key Laboratory of Urban Water Resource and Environment, Shenzhen Key Laboratory of Organic Pollution Prevention and Control, School of Civil and Environmental Engineering, Harbin Institute of Technology Shenzhen, Shenzhen 518055, China
| | - Haifeng Yuan
- Guangdong Provincial Key Laboratory of Nano-Micro Materials Research, School of Advanced Materials, Peking University Shenzhen Graduate School, Shenzhen 518055, China
| | - Simeng Li
- Guangdong Provincial Key Laboratory of Nano-Micro Materials Research, School of Advanced Materials, Peking University Shenzhen Graduate School, Shenzhen 518055, China
| | - Jinlong Li
- College of Chemistry and Chemical Engineering, Qiqihar University, Qiqihar 161006, China
| | - Dongxuan Guo
- College of Chemistry and Chemical Engineering, Qiqihar University, Qiqihar 161006, China
| | - Mei Hong
- Guangdong Provincial Key Laboratory of Nano-Micro Materials Research, School of Advanced Materials, Peking University Shenzhen Graduate School, Shenzhen 518055, China
| | - Shihe Yang
- Guangdong Provincial Key Laboratory of Nano-Micro Materials Research, School of Advanced Materials, Peking University Shenzhen Graduate School, Shenzhen 518055, China
- Institute of Biomedical Engineering, Shenzhen Bay Laboratory, Shenzhen 518055, China
| |
Collapse
|
5
|
van der Heijden O, Eggebeen JJJ, Trzesniowski H, Deka N, Golnak R, Xiao J, van Rijn M, Mom RV, Koper MTM. Li + Cations Activate NiFeOOH for Oxygen Evolution in Sodium and Potassium Hydroxide. Angew Chem Int Ed Engl 2024; 63:e202318692. [PMID: 38323697 DOI: 10.1002/anie.202318692] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2023] [Revised: 01/31/2024] [Accepted: 02/01/2024] [Indexed: 02/08/2024]
Abstract
The efficiency of electrolysis is reduced due to the sluggish oxygen evolution reaction (OER). Besides catalyst properties, electrocatalytic activity also depends on the interaction of the electrocatalyst with the electrolyte. Here, we show that the addition of small amounts of Li+ to Fe-free NaOH or KOH electrolytes activates NiFeOOH for the OER compared to single-cation electrolytes. Moreover, the activation was maintained when the solution was returned to pure NaOH. Importantly, we show that the origin of activation by Li+ cations is primarily non-kinetic in nature, as the OER onset for the mixed electrolyte does not change and the Tafel slope at low current density is ~30 mV/dec in both electrolytes. However, the increase of the apparent Tafel slope remains lower at increasing current densities in the presence of Li+. Based on electrochemical quartz crystal microbalance and in situ X-ray absorption spectroscopy measurements, we show that this reduction of non-kinetic effects is due to enhanced intercalation of sodium, water and hydroxide. This enhanced electrolyte penetration facilitates the OER, especially at higher current densities and for increased catalyst loading. Our work shows that mixed electrolytes where distinct cations can have different roles provide a simple and promising strategy towards improved OER rates.
Collapse
Affiliation(s)
- Onno van der Heijden
- Leiden Institute of Chemistry, Leiden University, Einsteinweg 55, 2333 CC, Leiden, the Netherlands
| | - Jordy J J Eggebeen
- Leiden Institute of Chemistry, Leiden University, Einsteinweg 55, 2333 CC, Leiden, the Netherlands
| | - Hanna Trzesniowski
- Department of Atomic-Scale Dynamics in Light-Energy Conversion, Helmholtz-Zentrum Berlin für Materialien und Energie, Albert-Einstein-Straße 15, 12489, Berlin, Germany
| | - Nipon Deka
- Leiden Institute of Chemistry, Leiden University, Einsteinweg 55, 2333 CC, Leiden, the Netherlands
| | - Ronny Golnak
- Department of Highly Sensitive X-Ray Spectroscopy, Helmholtz-Zentrum Berlin für Materialien und Energie, 14109, Berlin, Germany
| | - Jie Xiao
- Department of Highly Sensitive X-Ray Spectroscopy, Helmholtz-Zentrum Berlin für Materialien und Energie, 14109, Berlin, Germany
| | - Maartje van Rijn
- Leiden Institute of Chemistry, Leiden University, Einsteinweg 55, 2333 CC, Leiden, the Netherlands
| | - Rik V Mom
- Leiden Institute of Chemistry, Leiden University, Einsteinweg 55, 2333 CC, Leiden, the Netherlands
| | - Marc T M Koper
- Leiden Institute of Chemistry, Leiden University, Einsteinweg 55, 2333 CC, Leiden, the Netherlands
| |
Collapse
|
6
|
van der Heijden O, Park S, Vos RE, Eggebeen JJJ, Koper MTM. Tafel Slope Plot as a Tool to Analyze Electrocatalytic Reactions. ACS ENERGY LETTERS 2024; 9:1871-1879. [PMID: 38633990 PMCID: PMC11019648 DOI: 10.1021/acsenergylett.4c00266] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 01/26/2024] [Revised: 03/22/2024] [Accepted: 03/28/2024] [Indexed: 04/19/2024]
Abstract
Kinetic and nonkinetic contributions to the Tafel slope value can be separated using a Tafel slope plot, where a constant Tafel slope region indicates kinetic meaningfulness. Here, we compare the Tafel slope values obtained from linear sweep voltammetry to the values obtained from chronoamperometry and impedance spectroscopy, and we apply the Tafel slope plot to various electrocatalytic reactions. We show that similar Tafel slope values are observed from the different techniques under high-mass-transport conditions for the oxygen evolution reaction on NiFeOOH in 0.2 M KOH. However, for the alkaline hydrogen evolution reaction and the CO2 reduction reaction, no horizontal Tafel slope regions were observed. In contrast, we obtained the expected Tafel slope of 30 mV/dec for the HER on Pt in 1 M HClO4. We argue that widespread application of the Tafel slope plot, or similar numerical differentiation techniques, would result in an improved comparison of kinetic data for many electrocatalytic reactions when the traditional Tafel plot analysis is ambiguous.
Collapse
Affiliation(s)
- Onno van der Heijden
- Leiden Institute of Chemistry, Leiden University, 2333 CC Leiden, The Netherlands
| | - Sunghak Park
- Leiden Institute of Chemistry, Leiden University, 2333 CC Leiden, The Netherlands
| | - Rafaël E. Vos
- Leiden Institute of Chemistry, Leiden University, 2333 CC Leiden, The Netherlands
| | - Jordy J. J. Eggebeen
- Leiden Institute of Chemistry, Leiden University, 2333 CC Leiden, The Netherlands
| | - Marc T. M. Koper
- Leiden Institute of Chemistry, Leiden University, 2333 CC Leiden, The Netherlands
| |
Collapse
|
7
|
Xu J, Ruan J, Jian Y, Lao J, Li Z, Xie F, Jin Y, Yu X, Lee MH, Wang Z, Wang N, Meng H. Cobalt-Doping Induced Formation of Five-Coordinated Nickel Selenide for Enhanced Ethanol Assisted Overall Water Splitting. SMALL (WEINHEIM AN DER BERGSTRASSE, GERMANY) 2024; 20:e2305905. [PMID: 37926774 DOI: 10.1002/smll.202305905] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/13/2023] [Revised: 10/12/2023] [Indexed: 11/07/2023]
Abstract
To overcome the low efficiency of overall water splitting, highly effective and stable catalysts are in urgent need, especially for the anode oxygen evolution reaction (OER). In this case, nickel selenides appear as good candidates to catalyze OER and other substitutable anodic reactions due to their high electronic conductivity and easily tunable electronic structure to meet the optimized adsorption ability. Herein, an interesting phase transition from the hexagonal phase of NiSe (H-NiSe) to the rhombohedral phase of NiSe (R-NiSe) induced by the doping of cobalt atoms is reported. The five-coordinated R-NiSe is found to grow adjacent to the six-coordinated H-NiSe, resulting in the formation of the H-NiSe/R-NiSe heterostructure. Further characterizations and calculations prove the reduced splitting energy for R-NiSe and thus the less occupancy in the t2g orbits, which can facilitate the electron transfer process. As a result, the Co2 -NiSe/NF shows a satisfying catalytic performance toward OER, hydrogen evolution reaction, and (hybrid) overall water splitting. This work proves that trace amounts of Co doping can induce the phase transition from H-NiSe to R-NiSe. The formation of less-coordinated species can reduce the t2g occupancy and thus enhance the catalytic performance, which might guide rational material design.
Collapse
Affiliation(s)
- Jinchang Xu
- Guangdong Provincial Key Laboratory of Terahertz Quantum Electromagnetics GBA Branch of Aerospace Information Research Institute, Chinese Academy of Sciences, Guangzhou, 510700, China
| | - Jiaxi Ruan
- Guangdong Provincial Key Laboratory of Optical Fiber Sensing and Communications, Siyuan Laboratory, Guangzhou Key Laboratory of Vacuum Coating Technologies and New Energy Materials, Guangdong Provincial Engineering Technology Research Center of Vacuum Coating Technologies and New Energy Materials Department of Physics, Jinan University, Guangzhou, Guangdong, 510632, China
| | - Yongqi Jian
- Guangdong Provincial Key Laboratory of Optical Fiber Sensing and Communications, Siyuan Laboratory, Guangzhou Key Laboratory of Vacuum Coating Technologies and New Energy Materials, Guangdong Provincial Engineering Technology Research Center of Vacuum Coating Technologies and New Energy Materials Department of Physics, Jinan University, Guangzhou, Guangdong, 510632, China
| | - Jiayu Lao
- Guangdong Provincial Key Laboratory of Optical Fiber Sensing and Communications, Siyuan Laboratory, Guangzhou Key Laboratory of Vacuum Coating Technologies and New Energy Materials, Guangdong Provincial Engineering Technology Research Center of Vacuum Coating Technologies and New Energy Materials Department of Physics, Jinan University, Guangzhou, Guangdong, 510632, China
| | - Zilong Li
- Guangdong Provincial Key Laboratory of Optical Fiber Sensing and Communications, Siyuan Laboratory, Guangzhou Key Laboratory of Vacuum Coating Technologies and New Energy Materials, Guangdong Provincial Engineering Technology Research Center of Vacuum Coating Technologies and New Energy Materials Department of Physics, Jinan University, Guangzhou, Guangdong, 510632, China
| | - Fangyan Xie
- Instrumental Analysis & Research Center, Sun Yat-sen University, Guangzhou, Guangdong, 510275, China
| | - Yanshuo Jin
- Guangdong Provincial Key Laboratory of Optical Fiber Sensing and Communications, Siyuan Laboratory, Guangzhou Key Laboratory of Vacuum Coating Technologies and New Energy Materials, Guangdong Provincial Engineering Technology Research Center of Vacuum Coating Technologies and New Energy Materials Department of Physics, Jinan University, Guangzhou, Guangdong, 510632, China
| | - Xiang Yu
- Instrumental Analysis & Research Center, Jinan University, Guangzhou, Guangdong, 510632, China
| | - Ming-Hsien Lee
- Department of Physics, Tamkang University, New Taipei, 25137, Taiwan
| | - Zhenyou Wang
- Guangdong Provincial Key Laboratory of Terahertz Quantum Electromagnetics GBA Branch of Aerospace Information Research Institute, Chinese Academy of Sciences, Guangzhou, 510700, China
| | - Nan Wang
- Guangdong Provincial Key Laboratory of Optical Fiber Sensing and Communications, Siyuan Laboratory, Guangzhou Key Laboratory of Vacuum Coating Technologies and New Energy Materials, Guangdong Provincial Engineering Technology Research Center of Vacuum Coating Technologies and New Energy Materials Department of Physics, Jinan University, Guangzhou, Guangdong, 510632, China
| | - Hui Meng
- Guangdong Provincial Key Laboratory of Optical Fiber Sensing and Communications, Siyuan Laboratory, Guangzhou Key Laboratory of Vacuum Coating Technologies and New Energy Materials, Guangdong Provincial Engineering Technology Research Center of Vacuum Coating Technologies and New Energy Materials Department of Physics, Jinan University, Guangzhou, Guangdong, 510632, China
| |
Collapse
|
8
|
Xue J, Chen Z, Dang K, Wu L, Ji H, Chen C, Zhang Y, Zhao J. The plasmonic effect of Cu on tuning CO 2 reduction activity and selectivity. Phys Chem Chem Phys 2024; 26:2915-2925. [PMID: 38186081 DOI: 10.1039/d3cp05450k] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2024]
Abstract
Copper (Cu) has been widely used for catalyzing the CO2 reduction reaction (CO2RR), but the plasmonic effect of Cu has rarely been explored for tuning the activity and selectivity of the CO2RR. Herein, we conducted a quantitative analysis on the plasmon-generated photopotential (Ehv) of a Cu nanowire array (NA) photocathode and found that Ehv exclusively reduced the apparent activation energy (Ea) of reducing CO2 to CO without affecting the competitive hydrogen evolution reaction (HER). As a result, the CO production rate was enhanced by 52.6% under plasmon excitation when compared with that under dark conditions. On further incorporation with a polycrystalline Si photovoltaic device, the Cu NA photocathode exhibits good stability in terms of photocurrent and syngas production (CO : H2 = 2 : 1) within 10 h. This work validates the crucial role of the plasmonic effect of Cu on modulating the activity and selectivity of the CO2RR.
Collapse
Affiliation(s)
- Jing Xue
- Key Laboratory of Photochemistry, Beijing National Laboratory for 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
| | - Zhenlin Chen
- Key Laboratory of Photochemistry, Beijing National Laboratory for 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
| | - Kun Dang
- Key Laboratory of Photochemistry, Beijing National Laboratory for 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
| | - Lei Wu
- Key Laboratory of Photochemistry, Beijing National Laboratory for 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
| | - Hongwei Ji
- Key Laboratory of Photochemistry, Beijing National Laboratory for 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, Beijing National Laboratory for 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
| | - Yuchao Zhang
- Key Laboratory of Photochemistry, Beijing National Laboratory for 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, Beijing National Laboratory for 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
| |
Collapse
|
9
|
Wu L, Li Q, Dang K, Tang D, Chen C, Zhang Y, Zhao J. Highly Selective Ammonia Oxidation on BiVO 4 Photoanodes Co-catalyzed by Trace Amounts of Copper Ions. Angew Chem Int Ed Engl 2024; 63:e202316218. [PMID: 38069527 DOI: 10.1002/anie.202316218] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2023] [Indexed: 12/20/2023]
Abstract
High-efficient photoelectrocatalytic direct ammonia oxidation reaction (AOR) conducted on semiconductor photoanodes remains a substantial challenge. Herein, we develop a strategy of simply introducing ppm levels of Cu ions (0.5-10 mg/L) into NH3 solutions to significantly improve the AOR photocurrent of bare BiVO4 photoanodes from 3.4 to 6.3 mA cm-2 at 1.23 VRHE , being close to the theoretical maximum photocurrent of BiVO4 (7.5 mA cm-2 ). The surface charge-separation efficiency has reached 90 % under a low bias of 0.8 VRHE . This AOR exhibits a high Faradaic efficiency (FE) of 93.8 % with the water oxidation reaction (WOR) being greatly suppressed. N2 is the main AOR product with FEs of 71.1 % in aqueous solutions and FEs of 100 % in non-aqueous solutions. Through mechanistic studies, we find that the formation of Cu-NH3 complexes possesses preferential adsorption on BiVO4 surfaces and efficiently competes with WOR. Meanwhile, the cooperation of BiVO4 surface effect and Cu-induced coordination effect activates N-H bonds and accelerates the first rate-limiting proton-coupled electron transfer for AOR. This simple strategy is further extended to other photoanodes and electrocatalysts.
Collapse
Affiliation(s)
- Lei Wu
- Key Laboratory of Photochemistry, Beijing National Laboratory for 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
| | - Qianqian Li
- Key Laboratory of Photochemistry, Beijing National Laboratory for 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
| | - Kun Dang
- Key Laboratory of Photochemistry, Beijing National Laboratory for 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
| | - Daojian Tang
- Key Laboratory of Photochemistry, Beijing National Laboratory for 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, Beijing National Laboratory for 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
| | - Yuchao Zhang
- Key Laboratory of Photochemistry, Beijing National Laboratory for 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, Beijing National Laboratory for 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
| |
Collapse
|
10
|
Yu S, Liu D, Wang C, Li J, Yu R, Wang Y, Yin J, Wang X, Du Y. Nanosheet-assembled transition metal sulfides nanoflowers derived from CoMo-MOF for efficient oxygen evolution reaction. J Colloid Interface Sci 2024; 653:1464-1477. [PMID: 37804615 DOI: 10.1016/j.jcis.2023.10.006] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2023] [Revised: 09/24/2023] [Accepted: 10/01/2023] [Indexed: 10/09/2023]
Abstract
Oxygen evolution reaction (OER) is a multi-electron transfer process, whose intrinsic sluggish dynamic restricts the whole process of overall water splitting (OWS). To address this issue, a porous transition metal sulfide (TMS) catalyst with rich heterojunctions was prepared by vulcanization and trace Fe doping of CoMo-based metal-organic framework (MOF). In this work, the nanoflower composed of ultrathin 2D nanosheets anchored on a nickel foam presents a layered interface that contributes to the exposure of active regions. The resulting electrode denoted as Fe@CoMo2S4/Ni3S2/NF required a low overpotential (η10 = 167 mV @ 10 mA cm-2, η50 = 260 mV @ 50 mA cm-2) in 1.0 M KOH for OER and a small cell voltage (E = 1.513 V @ 10 mA cm-2) to power OWS when coupled with commercial Pt/C. It also exhibited splendid morphological and chemical stability with virtually invariant polarization curve and flower-like appearance after 1000 CV cycles, as well as long-term durability over 100 h with a constant current density of 10 mA cm-2. This work revealed the multi-anionic regulation mechanism in the surface reconstruction of sulfide electrocatalysts, and verified that Co/Mo/Ni-based oxysulfide was the true active substance of OER, which inspired the understanding and design of multi-anionic regulated electrocatalysts.
Collapse
Affiliation(s)
- Shudi Yu
- College of Chemistry, Chemical Engineering and Materials Science, Soochow University, 199 Renai Road, Suzhou 215123, PR China
| | - Dongmei Liu
- College of Chemistry, Chemical Engineering and Materials Science, Soochow University, 199 Renai Road, Suzhou 215123, PR China
| | - Cheng Wang
- College of Chemistry, Chemical Engineering and Materials Science, Soochow University, 199 Renai Road, Suzhou 215123, PR China
| | - Jie Li
- College of Chemistry, Chemical Engineering and Materials Science, Soochow University, 199 Renai Road, Suzhou 215123, PR China
| | - Rui Yu
- College of Chemistry, Chemical Engineering and Materials Science, Soochow University, 199 Renai Road, Suzhou 215123, PR China
| | - Yong Wang
- College of Chemistry, Chemical Engineering and Materials Science, Soochow University, 199 Renai Road, Suzhou 215123, PR China.
| | - Jiongting Yin
- College of Chemistry, Chemical Engineering and Materials Science, Soochow University, 199 Renai Road, Suzhou 215123, PR China
| | - Xiaomei Wang
- School of Chemical Biology and Materials Engineering, Suzhou University of Science and Technology, Suzhou 215009, PR China.
| | - Yukou Du
- College of Chemistry, Chemical Engineering and Materials Science, Soochow University, 199 Renai Road, Suzhou 215123, PR China.
| |
Collapse
|
11
|
Xie J, Wang F, Zhou Y, Dong Y, Chai Y, Dong B. Internal Polarization Field Induced Hydroxyl Spillover Effect for Industrial Water Splitting Electrolyzers. NANO-MICRO LETTERS 2023; 16:39. [PMID: 38032501 PMCID: PMC10689691 DOI: 10.1007/s40820-023-01253-9] [Citation(s) in RCA: 9] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/30/2023] [Accepted: 10/24/2023] [Indexed: 12/01/2023]
Abstract
The formation of multiple oxygen intermediates supporting efficient oxygen evolution reaction (OER) are affinitive with hydroxyl adsorption. However, ability of the catalyst to capture hydroxyl and maintain the continuous supply at active sits remains a tremendous challenge. Herein, an affordable Ni2P/FeP2 heterostructure is presented to form the internal polarization field (IPF), arising hydroxyl spillover (HOSo) during OER. Facilitated by IPF, the oriented HOSo from FeP2 to Ni2P can activate the Ni site with a new hydroxyl transmission channel and build the optimized reaction path of oxygen intermediates for lower adsorption energy, boosting the OER activity (242 mV vs. RHE at 100 mA cm-2) for least 100 h. More interestingly, for the anion exchange membrane water electrolyzer (AEMWE) with low concentration electrolyte, the advantage of HOSo effect is significantly amplified, delivering 1 A cm-2 at a low cell voltage of 1.88 V with excellent stability for over 50 h.
Collapse
Affiliation(s)
- Jingyi Xie
- State Key Laboratory of Heavy Oil Processing, College of Chemistry and Chemical Engineering, China University of Petroleum (East China), Qingdao, 266580, People's Republic of China
| | - Fuli Wang
- State Key Laboratory of Heavy Oil Processing, College of Chemistry and Chemical Engineering, China University of Petroleum (East China), Qingdao, 266580, People's Republic of China
| | - Yanan Zhou
- State Key Laboratory of Heavy Oil Processing, College of Chemistry and Chemical Engineering, China University of Petroleum (East China), Qingdao, 266580, People's Republic of China
| | - Yiwen Dong
- State Key Laboratory of Heavy Oil Processing, College of Chemistry and Chemical Engineering, China University of Petroleum (East China), Qingdao, 266580, People's Republic of China
| | - Yongming Chai
- State Key Laboratory of Heavy Oil Processing, College of Chemistry and Chemical Engineering, China University of Petroleum (East China), Qingdao, 266580, People's Republic of China.
| | - Bin Dong
- State Key Laboratory of Heavy Oil Processing, College of Chemistry and Chemical Engineering, China University of Petroleum (East China), Qingdao, 266580, People's Republic of China.
| |
Collapse
|
12
|
Ren X, Wang Q, Pu Y, Sun Q, Sun W, Lu L. Synergizing Spatial Confinement and Dual-Metal Catalysis to Boost Sulfur Kinetics in Lithium-Sulfur Batteries. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2023; 35:e2304120. [PMID: 37467076 DOI: 10.1002/adma.202304120] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/03/2023] [Revised: 07/09/2023] [Indexed: 07/21/2023]
Abstract
Sluggish kinetics and parasitic shuttling reactions severely impede lithium-sulfur (Li-S) battery operation; resolving these issues can enhance the capacity retention and cyclability of Li-S cells. Therefore, an effective strategy featuring core-shell-structured Co/Ni bimetal-doped metal-organic framework (MOF)/sulfur nanoparticles is reported herein for addressing these problems; this approach offers unprecedented spatial confinement and abundant catalytic sites by encapsulating sulfur within an ordered architecture. The protective shells exhibit long-term stability, ion screening, high lithium-polysulfide adsorption capability, and decent multistep catalytic conversion. Additionally, the delocalized electrons of the MOF endow the cathodes with superior electron/lithium-ion transfer ability. Via multiple physicochemical and theoretical analysis, the resulting synergistic interactions are proved to significantly promote interfacial charge-transfer kinetics, facilitate sulfur conversion dynamics, and inhibit shuttling. The assembled Li-S batteries deliver a stable, highly reversible capacity with marginal decay (0.075% per cycle) for 400 cycles at 0.2 C, a pouch-cell areal capacity of 3.8 mAh cm-2 for 200 cycles under a high sulfur loading, as well as remarkably improved pouch-cell performance.
Collapse
Affiliation(s)
- Xiaoyan Ren
- State Key Laboratory of Electroanalytical Chemistry, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun, Jilin, 130022, P. R. China
| | - Qin Wang
- State Key Laboratory of Electroanalytical Chemistry, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun, Jilin, 130022, P. R. China
- School of Applied Chemistry and Engineering, University of Science and Technology of China, Hefei, Anhui, 230026, P. R. China
| | - Yulai Pu
- State Key Laboratory of Electroanalytical Chemistry, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun, Jilin, 130022, P. R. China
- School of Applied Chemistry and Engineering, University of Science and Technology of China, Hefei, Anhui, 230026, P. R. China
| | - Qi Sun
- State Key Laboratory of Electroanalytical Chemistry, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun, Jilin, 130022, P. R. China
- School of Applied Chemistry and Engineering, University of Science and Technology of China, Hefei, Anhui, 230026, P. R. China
| | - Wenbo Sun
- State Key Laboratory of Electroanalytical Chemistry, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun, Jilin, 130022, P. R. China
| | - Lehui Lu
- State Key Laboratory of Electroanalytical Chemistry, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun, Jilin, 130022, P. R. China
- School of Applied Chemistry and Engineering, University of Science and Technology of China, Hefei, Anhui, 230026, P. R. China
| |
Collapse
|
13
|
Wu L, Ning M, Xing X, Wang Y, Zhang F, Gao G, Song S, Wang D, Yuan C, Yu L, Bao J, Chen S, Ren Z. Boosting Oxygen Evolution Reaction of (Fe,Ni)OOH via Defect Engineering for Anion Exchange Membrane Water Electrolysis Under Industrial Conditions. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2023; 35:e2306097. [PMID: 37607336 DOI: 10.1002/adma.202306097] [Citation(s) in RCA: 14] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/23/2023] [Revised: 08/10/2023] [Indexed: 08/24/2023]
Abstract
Developing non-precious catalysts with long-term catalytic durability and structural stability under industrial conditions is the key to practical alkaline anion exchange membrane (AEM) water electrolysis. Here, an energy-saving approach is proposed to synthesize defect-rich iron nickel oxyhydroxide for stability and efficiency toward the oxygen evolution reaction. Benefiting from in situ cation exchange, the nanosheet-nanoflake-structured catalyst is homogeneously embedded in, and tightly bonded to, its substrate, making it ultrastable at high current densities. Experimental and theoretical calculation results reveal that the introduction of Ni in FeOOH reduces the activation energy barrier for the catalytic reaction and that the purposely created oxygen defects not only ensure the exposure of active sites and maximize the effective catalyst surface but also modulate the local coordination environment and chemisorption properties of both Fe and Ni sites, thus lowering the energy barrier from *O to *OOH. Consequently, the optimized d-(Fe,Ni)OOH catalyst exhibits outstanding catalytic activity with long-term durability under both laboratory and industrial conditions. The large-area d-(Fe,Ni)OOH||NiMoN pair requires 1.795 V to reach a current density of 500 mA cm-2 at an absolute current of 12.5 A in an AEM electrolyzer for overall water electrolysis, showing great potential for industrial water electrolysis.
Collapse
Affiliation(s)
- Libo Wu
- Department of Physics and Texas Center for Superconductivity at the University of Houston (TcSUH), University of Houston, Houston, TX, 77204, USA
| | - Minghui Ning
- Department of Physics and Texas Center for Superconductivity at the University of Houston (TcSUH), University of Houston, Houston, TX, 77204, USA
| | - Xinxin Xing
- Department of Electrical and Computer Engineering and Texas Center for Superconductivity at the University of Houston (TcSUH), University of Houston, Houston, TX, 77204, USA
- School of Materials and Energy, Yunnan University, Kunming, Yunnan, 650091, China
| | - Yu Wang
- Department of Physics and Texas Center for Superconductivity at the University of Houston (TcSUH), University of Houston, Houston, TX, 77204, USA
- Materials Science and Engineering Program, University of Houston, Houston, TX, 77204, USA
| | - Fanghao Zhang
- Department of Physics and Texas Center for Superconductivity at the University of Houston (TcSUH), University of Houston, Houston, TX, 77204, USA
| | - Guanhui Gao
- Department of Materials Science and Nano-Engineering, Rice University, Houston, TX, 77005, USA
| | - Shaowei Song
- Department of Physics and Texas Center for Superconductivity at the University of Houston (TcSUH), University of Houston, Houston, TX, 77204, USA
| | - Dezhi Wang
- Department of Physics and Texas Center for Superconductivity at the University of Houston (TcSUH), University of Houston, Houston, TX, 77204, USA
| | - Chuqing Yuan
- Department of Physics and Texas Center for Superconductivity at the University of Houston (TcSUH), University of Houston, Houston, TX, 77204, USA
| | - Luo Yu
- Department of Physics and Texas Center for Superconductivity at the University of Houston (TcSUH), University of Houston, Houston, TX, 77204, USA
- Faculty of Materials Science and Chemistry, China University of Geosciences, Wuhan, Hubei, 430074, China
| | - Jiming Bao
- Department of Electrical and Computer Engineering and Texas Center for Superconductivity at the University of Houston (TcSUH), University of Houston, Houston, TX, 77204, USA
| | - Shuo Chen
- Department of Physics and Texas Center for Superconductivity at the University of Houston (TcSUH), University of Houston, Houston, TX, 77204, USA
| | - Zhifeng Ren
- Department of Physics and Texas Center for Superconductivity at the University of Houston (TcSUH), University of Houston, Houston, TX, 77204, USA
| |
Collapse
|
14
|
Yu H, Ke J, Shao Q. Two Dimensional Ir-Based Catalysts for Acidic OER. SMALL (WEINHEIM AN DER BERGSTRASSE, GERMANY) 2023; 19:e2304307. [PMID: 37534380 DOI: 10.1002/smll.202304307] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/22/2023] [Revised: 07/20/2023] [Indexed: 08/04/2023]
Abstract
Electrochemical water splitting in acidic media is one of the most promising hydrogen production technologies, yet its practical applications in proton exchange membrane (PEM) water electrolyzers are limited by the anodic oxygen evolution reaction (OER). Iridium (Ir)-based materials are considered as the state-of-the-art catalysts for acidic OER due to their good stability under harsh acidic conditions. However, their activities still have much room for improvement. Two-dimensional (2D) materials are full of the advantages of high-surface area, unique electrical properties, facile surface modification, and good stability, making the development of 2D Ir-based catalysts more attractive for achieving high catalytic performance. In this review, first, the unique advantages of 2D catalysts for electrocatalysis are reviewed. Thereafter, the classification, synthesis methods, and recent OER achievements of 2D Ir-based materials, including pure metals, alloys, oxides, and perovskites are introduced. Finally, the prospects and challenges of developing 2D Ir-based catalysts for future acidic OER are discussed.
Collapse
Affiliation(s)
- Hao Yu
- College of Chemistry, Chemical Engineering and Materials Science, Soochow University, Suzhou, Jiangsu, 215123, China
- Institute of Functional Nano & Soft Materials (FUNSOM), Jiangsu Key Laboratory for Carbon-Based Functional Materials & Devices, Soochow University, 199 Ren'ai Road, Suzhou, Jiangsu, 215123, China
| | - Jia Ke
- College of Chemistry, Chemical Engineering and Materials Science, Soochow University, Suzhou, Jiangsu, 215123, China
| | - Qi Shao
- College of Chemistry, Chemical Engineering and Materials Science, Soochow University, Suzhou, Jiangsu, 215123, China
| |
Collapse
|
15
|
Akbari N, Nandy S, Chae KH, Najafpour MM. Dynamic Changes of an Anodized FeNi Alloy during the Oxygen Evolution Reaction under Alkaline Conditions. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2023; 39:11807-11818. [PMID: 37556847 DOI: 10.1021/acs.langmuir.3c01540] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 08/11/2023]
Abstract
An efficient and durable oxygen evolution reaction (OER) catalyst is necessary for the water-splitting process toward energy conversion. The OER through water oxidation reactions could provide electrons for H2O, CO2, and N2 reduction and produce valuable compounds. Herein, the FeNi (1:1 Ni/Fe) alloy as foam, after anodizing at 50 V in a two-electrode system in KOH solution (1.0 M), was characterized by Raman spectroscopy, diffuse reflectance spectroscopy (DRS), X-ray absorption spectroscopy (XAS), X-ray diffraction (XRD), scanning electron microscopy (SEM), energy-dispersive X-ray spectrometry (EDX), transmission electron microscopy (TEM), high-angle annular dark-field imaging (HAADF)-scanning transmission electron microscopy (STEM) and used as an efficient and durable OER electrocatalyst in KOH solution (1.0 M). The overpotential for the onset of the OER based on extrapolation of the Tafel plot was 225 mV. The overpotentials for the current densities of 10 and 30 mA/cm2 are observed at 270 and 290 mV, respectively. In addition, a low Tafel slope is observed, 38.0 mV per decade, for the OER. To investigate the mechanism of the OER, in situ surface-enhanced Raman spectroscopy was used to detect FeNi hydroxide and characteristic peaks of H2O. Impurities in KOH can adsorb onto the electrode surface during the OER. Peaks corresponding to Ni(III) (hydr)oxide and FeO42- can be detected during the OER, but high-valent FeNi (hydr)oxides are unstable and reduce under the open circle potential. Metal hydroxide transformations during the OER and anion adsorption should be carefully considered. In addition, Fe3O4 may convert to γ-Fe2O3 during the OER. This study aims to offer logical perspectives on the dynamic changes that occur during the OER under alkaline conditions in an anodized FeNi alloy. These changes encompass variations in morphology, surface oxidation, the generation of high-valent species, and phase conversion during the OER.
Collapse
Affiliation(s)
- Nader Akbari
- Department of Chemistry, Institute for Advanced Studies in Basic Sciences (IASBS), Zanjan 45137-66731, Iran
| | - Subhajit Nandy
- Advanced Analysis Center, Korea Institute of Science and Technology, Seoul 02792, Republic of Korea
| | - Keun Hwa Chae
- Advanced Analysis Center, Korea Institute of Science and Technology, Seoul 02792, Republic of Korea
| | - Mohammad Mahdi Najafpour
- Department of Chemistry, Institute for Advanced Studies in Basic Sciences (IASBS), Zanjan 45137-66731, Iran
- Center of Climate Change and Global Warming, Institute for Advanced Studies in Basic Sciences (IASBS), Zanjan 45137-66731, Iran
- Research Center for Basic Sciences & Modern Technologies (RBST), Institute for Advanced Studies in Basic Sciences (IASBS), Zanjan 45137-66731, Iran
| |
Collapse
|