Surface -O terminated urchin-like TiO2/Ti3C2O (MXene) as high performance photocatalyst: Interfacial engineering and mechanism insight
Zirong Wang, Yue Zhang, Yiming Chen, Ping Wei, Hongjuan Wang, Hao Yu, Jianbo Jia, Kun Zhang, Chao Peng
Abstract
The surface groups of MXene act as a decisive role on the performance of MXene-based photocatalysts. In this work, TiO 2 nano-whiskers were grown in-situ on Ti 3 C 2 T x , through a hydrothermal and post-heat treatment process, meanwhile, the surface groups of Ti 3 C 2 T x were unified -O adsorption. The as-prepared urchin-like TiO 2 /Ti 3 C 2 O x composite have efficient activity for photocatalytic hydrogen evolution and degradation of levofloxacin (LEV). The optimized hydrogen evolution reaction (HER) performance reached 346.8 μmol g -1 h −1 , and the apparent quantum yield at 313 nm was 7.67%. Its hydrogen production performance and degradation rate of LEV were 9.7 and 7.7 folds higher than those of pure TiO 2 , respectively. The -O terminated Ti 3 C 2 O x achieving a work function about 0.3 eV larger than TiO 2 , as both DFT calculation and UPS measurement depicted. Therefore, the photogenerated e - /h + were separated at the TiO 2 /Ti 3 C 2 O x interface via Schottky junction, a large amount of e - was enriched on Ti 3 C 2 O x , which enabled the photocatalyst with remarkable charge separation and photocatalytic performance. Meanwhile, the reaction pathways of TiO 2 /Ti 3 C 2 O x photocatalytic HER and LEV degradation/mineralization were carefully investigated. This study underlines the significance of surface groups on photocatalysts composed of MXenes, and sheds light on the new approach to the rational design of high-efficiency MXene-based photocatalysts.