Self-doping synthesis of nano-TiO₂ with outstanding antibacterial properties under visible light

Nano-TiO₂ photocatalysis technology has attracted wide attention because of its safety, nontoxicity and long-lasting performance. However, traditional nano-TiO₂ has been greatly limited in its application because its wide band gap can only be activated by ultraviolet light (λ < 387 nm). In this paper, nano-TiO₂ was prepared by self-doping method. The synthesized nano-TiO₂ was a single anatase crystal type with a particle size of 10 nm and uniform size. In addition, nano-TiO₂ has high stability and good dispersion. More importantly, nano-TiO₂ exhibits excellent visible light (400-780 nm) activity due to the decrease of bandgap from 3.20 eV to 1.80 eV (less than 2.0 eV) and the presence of a large number of hydroxyl groups on the surface of the nanoparticles. In the antibacterial test, the antibacterial rate of both E.coli and S.aureus was close to 100 % under the irradiation of household low-power LED lamps, showing excellent antibacterial performance, indicating that the prepared nano-TiO₂ has broad application prospects in the field of bactericidal and bacteriostatic.