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

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 (1 1 0) and (0 1 0) 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.