Research Progress of High Entropy Materials as Water Electrolysis Catalysts in Recent Years

Hydrogen energy has drawn considerable attention in recent years, among which the efficient production of hydrogen energy from water electrolysis has become a hot research topic in this field. The oxygen evolution reaction (OER) and the hydrogen evolution reaction (HER) in water electrolysis are the core of the catalytic efficiency. High entropy materials have excellent combinatorial properties due to their "cocktail effect", high entropy effect, slow diffusion effect, and lattice distortion effect. They have outstanding catalytic effect in the process of water electrolysis, and thus become a hot research topic in recent years. This review combines the two hot topics by introducing the up-to-date research progress of high entropy materials in catalyzing water electrolysis. First, evaluation indexes of electrocatalytic performance are explained. Second, this review demonstrates specific materials from the classification of high entropy alloys, high entropy oxides and nitrided high entropy materials, which includes the structure of the materials and their specific catalytic performance. Finally, it summarizes the research progress of high entropy materials in water electrolysis catalysis as well as gives an outlook on the future design direction of the materials.