Enhanced interaction in TiO₂/BiVO₄ heterostructures via MXene Ti₃C₂ derived 2D-Carbon for highly efficient visible-light photocatalysis

摘要： Heterostructured photocatalysts play a significant role in contaminants removal by decreasing the recombination of the photo-induced charges. Herein, we presented novel TiO2/C/BiVO4 ternary hybrids employing a two-dimensional (2D) layered Ti3C2 MXene precursor, overcoming lattice mismatching of TiO2/BiVO4 binary heterostructures simultaneously. Raman and XPS analyses proved the strongly coupling effects of TiO2, carbon and BiVO4 components, and the heterostructures were identified by HRTEM results. Moreover, the ternary TiO2/C/BiVO4 composites exhibit excellent photocatalytic performance of Rhodamine B degradation, which is about 4 times higher than pure BiVO4 and twice than binary TiO2/BiVO4 heterostructures, reaching a reaction constant of 13.7×10-3 min-1 under visible-light irradiation (λ>420 nm). In addition, the possible mechanism for dye elimination was proposed that RhB molecule was directly oxidized by photo-induced holes (h+) on the BiVO4 components and superoxide radical (O2·-) generated from conduction-band electrons of the heterostructures. This work will provide possibilities for developing visible-light responsive nanomaterials for efficient solar utilization.