Visible-Light-Driven Catalytic Disinfection of Staphylococcus aureus Using Sandwich Structure g-C3N4/ZnO/Stellerite Hybrid Photocatalyst.

ABSTRACT

A novel g-C3N4/ZnO/stellerite (CNZOS) hybrid photocatalyst, which was synthesized by coupled hydro thermal-thermal polymerization processing, was applied as an efficient visible-light-driven photocatalyst against Staphylococcus aureus. The optimum synthesized hybrid photocatalyst showed a sandwich structure morphology with layered g-C3N4 (doping amount 40 wt%) deposited onto micron-sized ZnO/stellerite particles (ZnO average diameter ~18 nm). It had a narrowing band gap (2.48 eV) and enlarged specific surface area (23.05 m²/g). The semiconductor heterojunction effect from ZnO to g-C3N4 leads to intensive absorption of the visible region and rapid separation of the photogenerated electron-hole pairs. In this study, CNZOS showed better photocatalytic disinfection efficiency than g-C3N4/ZnO powders. The disinfection mechanism was systematically investigated by scavenger-quenching methods, indicating the important role of H2O2 in both systems. Furthermore, h⁺ was demonstrated as another important radical in oxidative inactivation of the CNZOS system. In respect of the great disinfection efficiency and practicability, the CNZOS heterojunction photocatalyst may offer many disinfection applications.