Degradation of tetracycline by photocatalysis combined with activated peroxymonsulfate over S-scheme BiVO4/Fe2O3 heterojunction

The S-scheme BiVO4/Fe2O3 composite catalyst was successfully prepared by the solgel method and low-temperature calcination method, which was used to degrade TC under the synergistic conditions of visible light and PMS. The BiVO4/Fe2O3/PMS/Light system has excellent TC degradation activity. It almost completely decomposes TC (20 ppm) in 30 minutes; the degradation rate of TC reaches 98.36 %, and it has good stability. Based on the analysis results of photoelectric properties, EPR test and active species capture experiment, combined with DFT calculations, the reaction mechanism of BiVO4/Fe2O3/PMS/Light system is proposed, that is, the S-scheme heterojunction effectively improves the separation and transfer of photogenerated charges, and retains the strong redox ability, and the synergistic effect of the cyclic conversion of transition metal ions Bi3+/Bi0 and Fe3+/Fe2+ can better activate PMS to generate more active species •SO4- and 1O2, thereby improving the reaction system catalytic activity. Therefore, the BiVO4/Fe2O3 synergistic visible light and PMS system is expected to be applied in the treatment of water pollutants.