Towards molecular understanding of surface and interface catalytic engineering in TiO/TiOF nanosheets photocatalytic antibacterial under visible light irradiation.

TiO/TiOF Z-scheme nanosheets have been successfully synthesized for photocatalytic antibacterial. The antibacterial efficiency of TiO/TiOF 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 TiO, TiOF, 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·HO and O 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 TiO/TiOF acts as an efficient transport path for photoexcited electrons from TiO to TiOF, 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.