Electrocatalytic oxygen evolution activities of metal chalcogenides and phosphides: Fundamentals, origins, and future strategies

The development of inexpensive and efficient electrocatalysts is key to commercializing energy-related electrocatalytic techniques such as water electrolyzers and metal-air batteries. In particular, novel oxygen evolution reaction (OER) pre-catalysts, such as transition metal chalcogenides (TMCs) and phosphides (TMPs), have evolved in recent years from traditional stable OER electrocatalysts, which show superior OER electrocatalytic performance compared with transition metal oxides (TMOs) or (oxy)hydroxides (TMOHs). In this feature article, we summarize recent advances in the development of TMC- and TMP-based OER electrocatalysts, as well as approaches to improve the OER performance in terms of morphology, structure, composition, surface engineering, lattice-strained and in-situ transformation in the electrolysis process. In particular, the electrochemical stability of TMCs and TMPs in alkaline electrolytes and the evolution of morphology, structure and composition under OER conditions are discussed. In the last section, we discuss the challenges that need to be addressed in this specific area of research and the implications for further research.