Isotype BiVO4 heterostructure and the effect of photo-sono induced electron-hole pair

Abstract

Owing to its suitable energy band and strong catalytic capacity, BiVO4 has received extensive attention in photocatalysis. Here, we suggest a straightforward approach to address the challenges of insufficient compatibility, poor charge transport characteristics, and limited surface adsorption properties commonly found in traditional BiVO4 photocatalysts. A heterojunction BiVO4 structure is developed by incorporating two distinct crystal phases within a single semiconducting material. A facile hydrothermal procedure is used to synthesize distinct crystalline phases of BiVO4 photocatalysts, viz., tetragonal, monoclinic, and monoclinic/tetragonal heterophase. The physicochemical characteristics of the pristine and isotype BiVO4 heterojunctions were characterized using various techniques. The photocatalytic activity of BiVO4 samples was examined by monitoring the degradation of rhodamine B (RhB). In order to boost the degradation reaction, ultrasonic sound waves are employed within the reaction medium. The present study examined the photocatalytic, sonocatalytic, and sonophotocatalytic activity of BiVO4 microcrystals in relation to the degradation of RhB dye. The results show that the crystalline phases of BiVO4 samples significantly influence the behaviour of photo-sono-induced charges. An interface in the monoclinic/tetragonal heterophase creates a spatial environment that facilitates charge transfer and enhances the separation of photo-sono-induced electron-hole pairs. The paper extensively examines the correlation between the behaviour of photo-sono-induced charge carriers and the level of sonophotocatalytic activity. This would provide greater insight into the intrinsic reasons for the enhancement in sonophotocatalytic activity.