Construction of Bi2S3/FeWO4 Z-Scheme heterojunction for efficient photo-Fenton degradation of antibiotics: Performance and degradation mechanism

Abstract

Herein, the Bi2S3/FeWO4 (BS/FWO) nanocomposite with excellent photo-Fenton activity was successfully prepared by dispersing FeWO4 nanoparticles onto the Bi2S3 nanorods using the hydrothermal method. Upon optimizing the ratio of Bi2S3 to FeWO4 in the BS/FWO photocatalyst, the degradation rate constants for tetracycline hydrochloride (TCH) and oxytetracycline (OTC) reach as high as 1.597 and 1.289 L·mg−1·min−1, respectively. These values were 5.4 and 6.1 times higher than those of pure FeWO4. The enhanced degradation performance of the BS/FWO composite could be attributed to the formed Z-scheme heterojunction, which facilitated the directional carrier transfer and inhibited the electron-hole recombination, thereby increasing the production of more reactive species. Active species capture experiments and electron paramagnetic resonance (EPR) analysis indicated that the BS/FWO heterojunction could generate superoxide radicals (·O2-) and hydroxyl radicals (·OH), which play a crucial role in the degradation of organics. Furthermore, the BS/FWO composite exhibited excellent stability across multiple reuse cycles. These findings propose a novel approach for wastewater treatment.