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 photocatalytic 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 (Ov) to significantly improve their photocatalytic inactivation performance against Staphylococcus aureus. The CuO/TiO2–H2 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 (O2) and a surface hydroxyl group or water (OH– or H2O), resulting in the formation of an active hydroxyl radical (·OH) and a superoxide radical anion (·O2–). In addition, the surface Ov can effectively reduce the conduction band and act as an electron capture center, thereby promoting the adsorption and activation of O2 and generating more active ·O2– 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.