Applications of MXene (Ti3C2Tx) in photocatalysis: a review

Abstract

MXenes are two-dimensional nanomaterials, which can be constructed from different elements. The rich interlayer groups, surface groups, and the flexible layer spacing of MXenes make them ideal catalysts. Among these, Ti₃C₂T_x has gained particular attention as a photocatalyst for photocatalytic CO₂ reduction reactions (CO₂RR), hydrogen evolution reactions (HER), and photocatalytic degradation reactions. The structure of Ti₃C₂T_x, hydrophilic surface functional groups, and the Gibbs free energy for hydrogen adsorption lead to the excellent photocatalytic HER performance of this material. Numerous surface defects on Ti₃C₂T_x also provide plentiful CO₂ adsorption sites for CO₂RR. It is the structure of two-dimensional nanomaterials and their high-speed electron transport channels that enable their excellent catalytic oxidation activity. However, at present, there are still challenges that limit their further application, the most significant of which is the material stability. In order to overcome this, the synthetic routes to prepare these photocatalysts need to be adapted.