The enhanced visible light driven photocatalytic inactivation of Escherichia coli with Z-Scheme Bi2O3/Bi2MoO6 heterojunction and mechanism insight

Abstract Recently, photocatalytic technology has been deemed as a prospective strategy for pathogenic microorganism removal. In this article, a nontoxcity Z-scheme Bi2O3/Bi2MoO6 (BO/BMO) heterojunction was rationally fabricated for photocatalytic inactivation against E. coli cells under visible light stimulation (λ > 420 nm). The 30% BO/BMO heterojunction presented the strongest bactericidal ability and the 7-log 10 cfu/mL of E. coli cells were absolutely inactivated within 5 h treated, which was much superior to the pure Bi2MoO6. The elevated photocatalytic performance of the BO/BMO heterojunctions could be ascribed to the higher spatially separation efficiency of the photoexcited electron-hole pairs and improved visible light absorption ability. The trapping experiments of reactive oxygen species (ROS) disclosed that the ·OH, e− and h+ played the predominant role in the E.coli inactivation. Moreover, the transfer of the photoexcited hole-electron pairs over the BO/BMO heterojunctions was verified to follow the Z-scheme model. The mechanism of photocatalytic inactivation of E.coli could be interpreted by the disruption of the cell membrane, leakage and destroy of the cellular biomoleculars (e.g. DNA and protein) as tested by the SEM and electrophoresis technology. This work may provide a promising avenue to explore a novel Bi2MoO6-based photocatalysts for pathogenic microorganisms removal.