The ultrasonic-induced-piezoelectric enhanced photocatalytic performance of ZnO/CdS nanofibers for degradation of bisphenol A

Highlights: • Piezo-photocatalyst of ZnO/CdS heterojunction was fabricated. • A piezoelectric field is produced in ZnO nanofibers by ultrasonic. • The piezoelectric effect can promote the separation of photoinduced charges. • ZnO/CdS exhibited high piezo-photocatalytic efficiency for BPA removal. -- Abstract: The separation rate of photoinduced carriers is a significant factor determining the photocatalytic activity. Herein, the nanofibers of ZnO/CdS hierarchical heterojunctions were fabricated, in which the transfer rate of photogenerated carriers was increased by the piezoelectric effect of ZnO. The photogenerated carriers can be generated by CdS under visible light illumination. The piezoelectric field produced by ZnO nanofibers under the ultrasonic can promote the separation of carries in CdS, greatly improving the photocatalytic performance. Under the synergy of ultrasonic and visible light, the optimal ZnO/CdS heterojunction could remove bisphenol A in water completely within 30 min, of which the rate (0.1557 min⁻¹) was 11.5 times higher than its photocatalytic rate. This work develops a strategy that coupling piezoelectric effect and visible-light driven photocatalytic by constructing a piezo-photocatalytic heterojunction for promoting the migration and separation of electron-hole pairs and realizing the enhancement of photocatalytic performance. Also, possible mechanism of the piezo-enhanced photocatalytic organic pollutants removal was revealed.