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

• Published in: ChemNanoMat : chemistry of nanomaterials for energy, biology and more biology and more, 2021-08, Vol.7 (8), p.910-915
• Main Authors: Song, Qinjun, Shen, Baojia, Yu, Jiaguo, Cao, Shaowen
• Format: Article
• Language: English
• Subjects: 3D heterojunction; CO2 reduction; Mxenes; Photocatalysis; TiO2
• ISSN: 2199-692X; 2199-692X
• DOI: 10.1002/cnma.202100155

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 Ti3C2Tx based on its 2D prototype as a precursor. TiO2 is in‐situ formed on the surface of Ti3C2Tx nanosheet by calcination, thereby obtaining a 3D hierarchical TiO2/Ti3C2Tx heterojunction. The rational design induces the intimate coupling of TiO2 and Ti3C2Tx, and macro‐mesopores in the hierarchical structure. The optimized sample exhibits a relatively high photocatalytic CH4 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 CO2 adsorption ability of Ti3C2Tx also ensures effective contact between CO2 molecules and photoinduced electrons from TiO2. This work demonstrates a facile strategy for the preparation of precursor‐induced functional materials toward various applications. A 3D hierarchical TiO2−Ti3C2 heterojunction was derived in situ from 3D Ti3C2 assemblies. Its excellent CO2 adsorption and electron migration ability obviously improved the performance of photocatalytic CO2 reduction.