Yang Qian, Du Jinyan, Li Jie, Wu Yuting, Zhou Yong, Yang Yang, Yang Dingming, He Huichao
State Key Laboratory of Environmental-Friendly Energy Materials, School of Materials Science and Engineering, Southwest University of Science and Technology, Mianyang 621010, China.
Ecomaterials and Renewable Energy Research Center, School of Physics, Nanjing University, Nanjing 211102, China.
ACS Appl Mater Interfaces. 2020 Mar 11;12(10):11625-11634. doi: 10.1021/acsami.9b21622. Epub 2020 Feb 28.
To reveal the role of oxygen vacancies in the solar water oxidation of α-FeO photoanodes, the kinetic and thermodynamic properties that are closely related to the water oxidation reaction of the α-FeO photoanode containing oxygen vacancies were investigated. Compared with the pristine -FeO photoanode, the presence of surface oxygen vacancies can improve the water oxidation activity and stability of the α-FeO photoanode simultaneously, but the bulk oxygen vacancies have a negative effect on the water oxidation performance of the α-FeO photoanode. In thermodynamics, our investigations revealed that the presence of surface oxygen vacancies narrows the space charge region width of the α-FeO photoanode, which could boost the charge separation and transfer efficiency of the α-FeO photoanode during water oxidation. Because the surface property and hydrophilicity of α-FeO are modified owing to the presence of surface oxygen vacancies, the water oxidation kinetics of the α-FeO photoanode with surface oxygen vacancies is obviously boosted. Our findings in the present work provide comprehensive understanding of the thermodynamic and kinetic differences for α-FeO photoanodes with and without oxygen vacancies for solar water oxidation.
为揭示氧空位在α-FeO光阳极太阳能水氧化中的作用，对与含氧量空位的α-FeO光阳极水氧化反应密切相关的动力学和热力学性质进行了研究。与原始α-FeO光阳极相比，表面氧空位的存在可同时提高α-FeO光阳极的水氧化活性和稳定性，但体相氧空位对α-FeO光阳极的水氧化性能有负面影响。在热力学方面，我们的研究表明，表面氧空位的存在使α-FeO光阳极的空间电荷区宽度变窄，这可以提高α-FeO光阳极在水氧化过程中的电荷分离和转移效率。由于表面氧空位的存在改变了α-FeO的表面性质和亲水性，具有表面氧空位的α-FeO光阳极的水氧化动力学明显增强。我们目前工作中的发现为有和无氧空位的α-FeO光阳极在太阳能水氧化方面的热力学和动力学差异提供了全面的理解。
