A rational strategy for CoFe layered double hydroxide oxygen evolution catalysts with high activity and stability

Oxygen evolution reaction (OER) catalyzed by non-precious metals and their compounds in alkaline environments are regarded as a key research topic for the use of water for hydrogen production to alleviate the global energy crisis. Cobalt-iron layered double hydroxide (CoFe-LDH) has attracted much attention as a potential high-performance oxygen evolution reaction catalyst. In this paper, we report a strategy to introduce metal elements M (M = Cu, K, Al, Cr and Zn) into CoFe-LDH to further enhance the OER performance. The experimental results show that CoFeK-15 exhibits the lowest overpotential (203 mV to reach 10 mA cm−2) and Tafel slope (77.1 mV dec−1) and maintains excellent catalytic activity after 50 h i-t test. Through the introduction of potassium ions, the electronic structure inside the catalyst underwent lattice distortion, resulting in a larger active surface area and exposure of more oxygen vacancies, which in turn accelerated the OER reaction. This study reveals the important influence of potassium doping on the electronic structure modification strategy to enhance the performance of OER and provides new ideas for the development of more efficient catalysts in the future.