Towards molecular understanding of surface and interface catalytic engineering in TiO2/TiOF2 nanosheets photocatalytic antibacterial under visible light irradiation

TiO2/TiOF2 Z-scheme nanosheets have been successfully synthesized for photocatalytic antibacterial. The antibacterial efficiency of TiO2/TiOF2 against E. coli and S. aureus were 99.90 % and 81.89 % at low material concentration (110 μg/mL), respectively, which are higher than those of pure TiO2, TiOF2, and Degussa P25. In situ molecular spectroscopy results demonstrate that the microstructure of the synthesized material can be reconstructed and optimized to enhance the exposure of the active sites·H2O and O2 are effectively adsorbed on the catalyst surface and activated to form OH…Ti and O…Ti surface active species. Furthermore, the dense interface formed in TiO2/TiOF2 acts as an efficient transport path for photoexcited electrons from TiO2 to TiOF2, and thus accelerates the formation of reactive oxygen species. Finally, the mechanism of bacterial inactivation is systematically discussed considering the main active substances, cell morphological changes, and activity of antioxidant enzymes.