Two-dimensional MXene-based and MXene-derived photocatalysts: Recent developments and perspectives

Since their discovery in 2011, 2D MXenes have gained tremendous traction for their flexible elemental composition, unique 2D-layered structure, large surface area, abundant surface terminations, and excellent photoelectronic properties. In particular, the latest advances demonstrate that MXene-based and MXene-derived photocatalysts are the most advantageous and novel materials in the photocatalytic field. In this review, we summarize recent studies on the preparation of MXene-based and MXene-derived photocatalysts, including mechanical/ultrasonic mixing, electrostatic self-assembly, hydrothermal/solvothermal preparations, and calcination approaches. In addition, we present a comprehensive review of the environmental and energy applications of MXene-based and MXene-derived photocatalysts, including organic pollutant degradation, water splitting for H2 evolution, CO2 reduction, nitrogen fixation, H2O2 production, antibacterial application, desulfurization and denitrogenation of fuels. The roles of MXene as a co-catalyst or precursor in photocatalytic applications are addressed herein. Finally, the lingering challenges and perspectives on the study of MXenes in the future are presented.