2D-Layered Carbon/TiO₂ Hybrids Derived from Ti₃C₂MXenes for Photocatalytic Hydrogen Evolution under Visible Light Irradiation

TiO₂ is a promising photocatalytic material for hydrogen generation. However, the fast recombination of electron–holes restricts the photocatalytic performance of TiO₂. Herein, this study demonstrates a 2D-layered carbon/TiO₂ (C/TiO₂) architecture via CO₂ oxidation of 2D-Ti₃C₂, in which the 2D carbon layers provide electron transport channels and improve the hole–electron separation efficiency. Compared to Ti₃C₂ support, the thickness of derived carbon supports is significantly reduced, which enhances the light intensity arriving at the surface of TiO₂. The oxidation parameters are investigated systematically. It is found that high temperature and high CO₂ gas flux lead to the formation of crystal TiO₂ and the oxidation of carbon layers. The bandgap of 2D-layered C/TiO₂ samples is ranged from 2.83 to 2.89 eV. The 2D-layered C/TiO₂ delivers enhanced photocatalytic activity compared with pure TiO₂ catalysts. The optimal photocatalytic hydrogen evolution rate of 2D-layered C/TiO₂ is up to 24.04 µmol h⁻¹, which is about 89 times higher than that of pure TiO₂. This research broadens the applications of C/TiO₂ hybrids and provides new approach to synthesize novel 2D-layered materials for photocatalytic applications.