Research progress of MXene-based catalysts for electrochemical water-splitting and metal-air batteries

MXenes, a rising family of two-dimensional (2D) materials, are characterized by a unique combination of high electrical conductivities, hydrophilicity, and adjustable surface properties, which exhibit great potential in overall water splitting and metal-air batteries as electrocatalysts. In this review, the preparation methods, and some relevant properties of MXenes are summarized, and their applications in electrocatalysis are systematically reviewed from theoretical calculations to experimental investigations, including hydrogen evolution reaction (HER), oxygen evolution reaction (OER), oxygen reduction reaction (ORR), and bifunctional activity. The strategies for improving their electrocatalytic performance and electrocatalytic mechanisms are discussed, and the challenges and prospects relative to the applications of MXenes in electrocatalysis are also presented.