Preparation,characterization and antibacterial properties of cobalt doped titania nanomaterials

Cobalt-doped titania (Co-TiO₂) nanomaterials were synthesized by the sol-gel method at different calcination temperatures. Using Escherichia coli (a), Staphylococcus aureus (b) and Candida albicans (c) as target strains, the antibacterial activity in visible light of the nanomaterials were studied. Co-TiO₂ nanomaterials were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), UV-Vis diffuse reflectance spectroscopy (DRS), Fourier transform infrared spectrum (FT-IR) and X-ray photoelectron spectroscopy (XPS). The Co ions in the Co-TiO₂ nanomaterial exist in the form of CoTiO₃ phase. The antibacterial properties of Co-TiO₂ nanomaterials on E. coli (a), S. aureus (b) and C. albicans (c) were investigated with the oscillating flask method and the inhibition zone method. The nanomaterials calcined at 600℃ exhibit excellent antibacterial activity. The bacteriostatic rates for E. coli, S. aureus and C. albicans reached 99.5%, 91.3% and 93.4% respectively. The diameters of the antibacterial rings were up to 36 mm, 37 mm, 30 mm respectively, and the clarity of the ring was clear. The antibacterial properties of Co-TiO₂ nanomaterials were compared with those of traditional silver sol, zinc oxide sol and Zn-doped TiO₂ nanomaterials The mechanism of the influences of Co ions doping on the antibacterial activity of TiO₂ nanomaterials was also discussed. The doping of Co ions inhibits the particle size of the antibacterial agent and extends the photocatalytic response range, thereby improving the photocatalytic performance of the antibacterial agent.