Abstract:

Zinc oxide, as a photocatalytic antibacterial material, has attracted much attention due to its low cost and high safety. In this paper, a series of TiO₂-ZnO composite antibacterial materials with different TiO₂ mole doping （0%, 5%, 10%, 15%, 20%） were prepared by ultrasonic calcination method. The results show that TiO₂-ZnO composite is composed of hexagonal wurtzite ZnO and anatase TiO₂. The addition of TiO₂ generates new Zn-O-Ti bonds. TiO₂ particles are continuously and evenly distributed on the surface of ZnO, and the size of ZnO is 2-3 μm. The colony of Escherichia coli （E. coli） cultured for 12 h shows that the antibacterial ability of pure ZnO is weak. With the increase of TiO₂ addition, the number of colonies decreases, and the antibacterial ability of TiO₂-ZnO gradually increases. The antibacterial ability of TiO₂ ZnO composite antibacterial material with TiO₂ doping mole ratio of 15% is the strongest. Under the photocatalytic reaction, the sterilization efficiency of TiO₂-ZnO doped with 15% mole ratio of TiO₂ reaches 100% in 15 min. TiO₂-ZnO rapidly destroy the cell membrane of Escherichia coli under the light, causing serious deformation of Escherichia coli and the outflow of cytoplasm, thus killing bacteria. The addition of TiO₂ significantly improves the sterilization ability of ZnO antibacterial materials.

Key words: ZnO, TiO₂, compound material, antibacterial performance, photocatalysis, Escherichia coli