A 3D Hierarchical Ti3C2Tx/TiO2 Heterojunction for Enhanced Photocatalytic CO2 Reduction

Abstract The construction of three‐dimensional (3D) hierarchical photocatalysts from two‐dimensional (2D) nanosheets has attracted lots of interest due to its unique structural properties. Herein we design a 3D hierarchical structure of Ti 3 C 2 T x based on its 2D prototype as a precursor. TiO 2 is in‐situ formed on the surface of Ti 3 C 2 T x nanosheet by calcination, thereby obtaining a 3D hierarchical TiO 2 /Ti 3 C 2 T x heterojunction. The rational design induces the intimate coupling of TiO 2 and Ti 3 C 2 T x , and macro‐mesopores in the hierarchical structure. The optimized sample exhibits a relatively high photocatalytic CH 4 evolution activity of 4.41 μmol ⋅ g −1 ⋅ h −1 , which is almost twice that of P25 (2.32 μmol ⋅ g −1 ⋅ h −1 ). The enhanced photocatalytic performance arises from the more efficient electron‐hole separation and better light harvesting of the 3D hierarchical structure. Moreover, the excellent CO 2 adsorption ability of Ti 3 C 2 T x also ensures effective contact between CO 2 molecules and photoinduced electrons from TiO 2 . This work demonstrates a facile strategy for the preparation of precursor‐induced functional materials toward various applications.