Peroxymonosulfate-assisted for facilitating photocatalytic degradation performance of 2D/2D WO3/BiOBr S-scheme heterojunction

Abstract

The Sulfate-mediated photocatalysis (SR-photo) technology was considered to be a rapid, efficient and green environmental treatment technology. In this study, the two-dimensional/two-dimensional WO3/BiOBr S-scheme heterojunction (2D/2D WOB) were prepared through the hydrothermal method. Subsequently, multiple characterization techniques confirmed that WO3 was successfully loaded on the surface of BiOBr nanosheets and an intimate interaction was formed. Tetracycline (TC) and enrofloxacin (ENR) were used as target pollutants to evaluate the degradation performance of the WOB/SR-photo system. The 1:2 WOB heterojunction exhibited the highest degradation activity, and the remove rate of TC and ENR reached 98% and 87%, respectively, within 60 min. Moreover, radical quenching experiments and electron paramagnetic resonance (EPR) results implied that the 1O2, h+, and ·O2 − played critical roles in the WOB/SR-photo system. The intermediate products of TC degradation were analyzed by liquid chromatography-mass spectrometer (LC-MS), and three possible degradation pathways were inferred. The photoelectrochemical measurement, photoluminescence (PL) and time-resolved PL confirmed that 1:2 WOB composite exhibited the highest transfer rate of charge carriers. Finally, based on the results of UV-DRs, Mott-Schottky curve and Density functional theory (DFT) calculations, the S-scheme WOB heterostructure was determined, and the degradation mechanism of the WOB/SR-photo system was also clarified. This study confirmed the superiority of the SR-photo system and brought dawn to the application of numerous photocatalysts with insufficient performance.