Construction of a novel efficient Z-scheme BiVO4/EAQ heterojunction for the photocatalytic inactivation of antibiotic-resistant pathogens: Performance and mechanism

Abstract

To improve the bactericidal capability of the BiVO4 photocatalyst, a novel Z-scheme bismuth vanadate/2-ethylanthraquinone (BiVO4/EAQ) photocatalyst was constructed to inactivate antibiotic-resistant pathogens and degrade antibiotic-resistance genes (ARGs) in aqueous environments. The introduction of EAQ into BiVO4 enhanced the photocatalytic performance by promoting charge generation and inhibiting electron-holepair recombination. Based on the results of electron paramagnetic resonance (EPR) and fluorescent probe quantitative analyses, 60 %-BiVO4/EAQ was confirmed to be a Z-scheme heterojunction photocatalyst. The 60 %-BiVO4/EAQ composite exhibited the highest inactivation efficiency toward Shigella flexneri HL, with complete inactivation within 150 min. Scavenger experiments and radical concentration quantification assays indicated that O2− and h+ performed the major roles during photocatalytic inactivation, followed by OH. Moreover, the extracellular tetA resistance gene was almost completely degraded after a 6-hour photocatalysis reaction. The fragmentation pathway of circular DNA under photocatalysis reaction was observed with the aid of atomic force microscopy (AFM), which might also be the mechanism of ARG decomposition. Furthermore, BiVO4/EAQ composite performed good photocatalytic inactivation performance in actual water matrices. This work provides an efficient biohazard inactivation method.