MXenes for catalysis: current developments in photocatalysis and electrocatalysis

Abstract

In recent years, MXenes have achieved remarkable progress in catalysis owing to their distinctive physicochemical properties, such as excellent electrical conductivity, tunable surface functional groups, and unique two-dimensional layered structures. This paper systematically reviews the preparation methods of MXenes (highlighting solution etching with HF as a typical approach and electrochemical etching) and advanced modification strategies (such as heterojunction construction, heteroatom doping, single-atom/diatomic catalyst loading and oxygen vacancy engineering). It focuses on key applications of MXene-derived catalysts in electrocatalysis and photocatalysis, emphasizing catalytic performance metrics such as overpotential, Tafel slope, ammonia/CO yield, and stability. Furthermore, it discusses the common catalytic mechanisms of MXene-based materials from the perspectives of electronic structure regulation and interfacial engineering. Finally, this paper addresses the major challenges currently hindering the practical application of the MXene-based catalysts, such as the environmental toxicity of traditional etching processes, their structural instability in water/oxygen environments, and the trade-offs between the active site density, conductivity, and mass transfer efficiency, while offering a perspective on future progress directions for advancing the development of efficient and sustainable MXene-based catalytic systems.