Photocatalytic Applications of Two-Dimensional Ti₃C₂ MXenes: A Review

Two-dimensional (2D) Ti3C2 MXenes have aroused tremendous attention as frontier materials for energy storage, solar energy conversion, and environmental remediation because they exhibit high elemental abundance in the earth, a unique layered microstructure, abundant surface functional groups, and prominent electrical conductivity and optical properties. The present study summarizes and discusses the most recent advancements in the synthesis methods of Ti3C2 MXenes; the routes of intercalation, exfoliation, and cutting for multilayered Ti3C2 to obtain its delaminated compounds and quantum dots; and their photocatalysis applications. Given the differences of applied Ti3C2 on morphology and size, high-efficiency Ti3C2-based Schottky junction photocatalysts and its derivative photocatalysts are generalized and discussed. The advantages of Ti3C2 MXenes in synthesizing high-efficiency photocatalysts are analyzed, consisting of electronic acceptor, substrate, light harvesting, cocatalyst, and precursor. Lastly, the lingering challenges and directions for the subsequent Ti3C2-based photocatalyst development are proposed.