Surface-O terminated urchin-like TiO2/Ti3C2OX (MXene) as high performance photocatalyst: Interfacial engineering and mechanism insight

The surface groups of MXene act as a decisive role on the performance of MXene-based photocatalysts. In this work, TiO2 nano-whiskers were grown in-situ on Ti3C2TX, through a hydrothermal and post-heat treatment process, meanwhile, the surface groups of Ti3C2TX were unified-O adsorption. The as-prepared urchin-like TiO2/ Ti3C2OX composite have efficient activity for photocatalytic hydrogen evolution and degradation of levofloxacin (LEV). The optimized hydrogen evolution reaction (HER) performance reached 346.8 mu mol 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 TiO2, respectively. The-O terminated Ti3C2OX achieving a work function about 0.3 eV larger than TiO2, as both DFT calculation and UPS measurement depicted. Therefore, the photogenerated e-/h+ were separated at the TiO2/Ti3C2OX interface via Schottky junction, a large amount of e -was enriched on Ti3C2OX, which enabled the photocatalyst with remarkable charge separation and photocatalytic performance. Meanwhile, the reaction pathways of TiO2/Ti3C2OX photocatalytic HER and LEV degradation/ mineralization were carefully investigated. This study underlines the significance of surface groups on photo -catalysts composed of MXenes, and sheds light on the new approach to the rational design of high-efficiency MXene-based photocatalysts.

Automated summary

The surface groups of MXene play a crucial role in the performance of MXene-based photocatalysts. In this study, TiO2 nano-whiskers were grown on Ti3C2TX through a hydrothermal and post-heat treatment process, with the surface groups of Ti3C2TX unified-O adsorption. The resulting urchin-like TiO2/Ti3C2OX composite exhibited efficient activity for photocatalytic hydrogen evolution and levofloxacin (LEV) degradation.