Enhanced LED-light-driven photocatalytic antibacterial by g-C3N4/BiOI composites

g-C3N4/BiOI composites with different ratios were prepared by in-situ generation route at room temperature and applied in antibacterial investigation. Detailed information of the composites was characterized by XRD, TEM, HRTEM, SEM, EDS, BET, XPS, FT-IR, UV-Vis, photocurrent and EIS. The obtained g-C3N4/BiOI composites presented excellent antibacterial performance toward Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus) under LED track light, with the complete inactivation of bacterial within 30min. The decomposition of bacterial cells was observed by SEM. The bacterial mechanism was investigated by trapping experiments: holes (h(+)), superoxide anion free radical (O-2(-)) and hydrogen peroxide (H2O2) were identified as active species for bacterial inactivation, and h(+) had a main effect in the antibacterial process. The enhanced photocatalytic activities were assigned to an efficient separation and transition of electrons (e(-)) and h(+) in photocatalytic antibacterial process. This work indicated the g-C3N4/BiOI composites are promising photocatalytic antibacterial materials for water disinfection.