Crystal regulation of BiVO4 for efficient photocatalytic degradation in g-C3N4/BiVO4 heterojunction

Abstract

The radicals generated by photocatalysis are widely used in environmental pollution treatment due to their super oxidizing ability and non-polluting characteristics, and are controlled through band potential and electron transfer types. Herein, through crystal engineering, we developed a novel g-C3N4/BiVO4 containing BiVO4 with different crystal structures, which can generate superoxide radicals and hydroxyl radicals under light irradiation. The (110) and (010) of BiVO4 crystal face showed different electron transfer paths, which proves that the existence of the build-in electric field is the internal driving force of S-scheme electron transfer. S-scheme electron transfer can reduce the recombination of electrons and holes, and promote the photocurrent density, and type Ⅱ electron transfer can reduce the decomposition of active oxides. By adjusting the ratio of S-scheme and type Ⅱ electron transfer, the addition of 1 % g-C3N4 could increase the photocatalytic activity of organic pollutants by 2.3 times. And the gap between the interfaces of g-C3N4 and BiVO4 also increases the adsorption capacity of pollutants. This research provides a theoretical basis for the regulation of the crystal structure and interface electron transfer in photocatalysis.