Dai Yawen, Yu Jie, Zhang Zhenbao, Cheng Chun, Tan Peng, Shao Zongping, Ni Meng
Department of Building and Real Estate, The Hong Kong Polytechnic University, Hung Hom, Kowloon, 999077, Hong Kong, P. R. China.
Department of Thermal Science and Energy Engineering, University of Science and Technology of China, Hefei 230026, Anhui, P. R. China.
ACS Appl Mater Interfaces. 2021 Jan 20;13(2):2799-2806. doi: 10.1021/acsami.0c21859. Epub 2021 Jan 7.
The electrochemical oxygen evolution reaction (OER) is of great significance for energy conversion and storage. The hybrid strategy is attracting increasing interest for the development of highly active OER electrocatalysts. Regarding the activity enhancement mechanism, electron coupling between two phases in hybrids has been widely reported, but the interfacial elemental redistribution is rarely investigated. Herein, we developed a CeO/LaFeO hybrid electrocatalyst for enhanced OER activity. Interestingly, a selective interfacial La diffusion from LaFeO to CeO was demonstrated by the electron energy loss spectra and elemental mapping. This redistribution of cations triggers the change of the chemical environment of interface elements for charge compensation because of the electroneutrality principle, which results in increased oxygen vacancies and high-valent Fe species that promote the OER electrocatalysis. This mechanism might be extended to other hybrid systems and inspire the design of more efficient electrocatalysts.
