Achieving excellent photocatalytic degradation of pollutants by flower-like SrBi4Ti4O15/BiOCl heterojunction: The promotion of piezoelectric effect

Combining photocatalyst with piezoelectric materials is an effective way to promote the performance of photocatalysis. Herein, a flower-like SrBi4Ti4O15/BiOCl composite is proposed and its photocatalytic degradation performance is effectively improved by piezoelectric effect. SrBi4Ti4O15/BiOCl heterojunction is prepared by molten salt method and hydrothermal method, and the polarization is carried out under the action of direct current high voltage electric field. Piezoelectric effect offers a built-in polarization field for improving the separation efficiency of photogenerated electrons and holes. Hence, under the synergistic action of ultrasound and light, the degradation rate constant of polarized SrBi4Ti4O15/BiOCl to RhB dye reaches 0.7313 min−1, which is 13.13 and 2.53 times that of pure SrBi4Ti4O15 and SrBi4Ti4O15/BiOCl under light only, exceeding almost vast majority piezo-photocatalysts reported. This study provides an efficient and feasible piezo-photocatalyst for pollutant treatment, and contributing to comprehending the mechanism of piezoelectric effect to improve the photocatalytic performance.