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 the removal of contaminants by decreasing the recombination of the photo-induced charges. Herein, we presented novel TiO2/C/BiVO4 ternary hybrids employing a 2D layered Ti3C2 MXene precursor, overcoming the lattice mismatching of TiO2/BiVO4 binary heterostructures simultaneously. Raman and XPS analyses proved the strong coupling effects of TiO2, carbon and BiVO4 components, and the heterostructures were identified from high-resolution transmission electron microscopy results. Moreover, the ternary TiO2/C/BiVO4 composites exhibit excellent photocatalytic performance of Rhodamine B degradation, which is about four times higher than pure BiVO4 and twice that of binary TiO2/BiVO4 heterostructures, reaching a reaction constant of 13.7 x 10(-3) min(-1) under visible-light irradiation (lambda > 420 nm). In addition, for the possible mechanism for dye elimination it was proposed that RhB molecule be directly oxidized by photo-induced holes (h(+)) on the BiVO4 components and superoxide radical (O-2(center dot-) ) generated from conduction band electrons of the heterostructures. This work will provide possibilities for developing visible-light responsive nanomaterials for efficient solar utilization.