High entropy materials based electrocatalysts for water splitting: Synthesis strategies, catalytic mechanisms, and prospects

Among various electrocatalysts, high entropy materials (HEMs) have attracted great attention due to the distinctive designing concept and unique properties with captivating electrocatalytic activity and stability. To date, HEMs have been a new family of advanced electrocatalysts in the research field of water electrolysis. In this work, the structural features and synthesis strategies of high entropy catalysts are reviewed, especially, their performances for catalyzing hydrogen evolution reaction (HER) and oxygen evolution reaction (OER) in water electrolysis are presented, in which the crucial roles of structure, composition, multi-sites synergy, and "four core effects " for enhancing catalytic activity, stability, and resistance of electrochemical corrosion are introduced. Besides, the design tactics, main challenges, and future prospects of HEM-based electrocatalysts for HER and OER are discussed. It is expected to provide valuable information for the development of low-cost efficient HEM-based electrocatalysts in the field of water electrolysis.