Visible-light-driven Photocatalytic Bacterial Disinfection by Bismuth Vanadate Nanotubes

Studies on visible-light-driven (VLD) photocatalysis indicate its excellent potential as an alternative bacterial disinfection process. In this study, bismuth vanadate (BiVO4) nanotube (BV-NT) was synthesized by a template-free solvothermal method. The BV-NT showed remarkable VLD photocatalytic disinfection to Escherichia coli K-12. Various scavengers were used to detect the major reactive charged and oxidative species involving in photocatalytic bacterial disinfection. Results showed that .OHb and reactive species generated at the conduction band (i.e. e(-) and .O-2) have no significant effect on the photocatalytic bacterial disinfection. The h(+) and .OHb, were the dominant reactive species in the VLD photocatalytic disinfection, while H2O2 generated from valence band only played a minor role. The individual role of h(+) and .OHS, was confirmed by adopting F- surface modification and anaerobic experiments. With the "partition system" and transmission electron microscopic studies, it was found that the effective bacterial inactivation required the bacteria cell direct contact with the BV-NT. Based on the band structure of BV-NT, reactive species cannot produce from the conduction band, and only the reactive species generated from the valence band involve in the VLD photocatalytic bacterial disinfection by BV-NT.