CuO/TiO2 Nanobelt with Oxygen Vacancies for Visible-Light-Driven Photocatalytic Bacterial Inactivation

Bacterial infection can induce a variety of deadly diseases that seriously threaten human life and health. TiO2 is extensively employed as a broad-spectrum antibacterial photo catalytic material for the inactivation of bacteria. However, a wide band-gap nature has limited the effectiveness of TiO2 to only the UV-light range. In addition, photogenerated electrons and holes can recombine quickly, inducing low antibacterial efficiency. Here, we fabricated a CuO/ TiO2 nanobelt by an impregnation method and introduced surface oxygen vacancies (O-v) to significantly improve their photocatalytic inactivation performance against Staphylococcus aureus. The CuO/ TiO2-H-2 catalyst contains more Ov and exhibits excellent antibacterial properties against S. aureus. The antibacterial efficiency is 32.2 and 99.4 times those of CuO/ TiO2 and bare TiO2, respectively, under light irradiation. The photogenerated electron-hole pairs react with molecular oxygen (O-2) and a surface hydroxyl group or water (OH- or H2O), resulting in the formation of an active hydroxyl radical (center dot OH) and a superoxide radical anion (center dot O-2(-)). In addition, the surface O-v can effectively reduce the conduction band and act as an electron capture center, thereby promoting the adsorption and activation of O-2 and generating more active center dot O-2(-) species. This work indicates the efficient antibacterial activity of a CuO/TiO2 nanobelt with Ov and provides a feasible approach for the development of highly efficient antibacterial nanomaterials in the medical field.