Abstract: Cobalt (Co) and TiO₂ were doped together to synthesize C@TiCoO₃@TiO₂ by sol-gel method and then characterized by scanning electron microscopy (SEM), X-ray diffraction spectroscopy (XRD), X-ray photoelectron spectroscopy (XPS) and UV-Vis diffuse reflection spectroscopy (UV-Vis DRS). The results of SEM and XPS showed that the material was in bulk form and composed of Ti, O, C and Co elements. XRD mapping showed that C@TiCoO₃@TiO₂ existed mainly in the form of anatase crystals with a large specific surface area. The map of UV-Vis DRS showed that C@TiCoO₃@TiO₂ had a wide range of visible light absorption (762 nm), a narrow gap of band (1.63 eV) and a superior response to visible light. 5 mg/mL C@TiCoO₃@TiO₂ could completely kill Staphylococcus aureus and Escherichia coli under LED visible light irradiation (power 7 W) for 60 and 100 minutes, respectively. The cytotoxi-city test showed that the material had good biocompatibility. It showed that the C@TiCoO₃@TiO₂ nanocomposite had been successfully synthesized and would have potential value as an antimicrobial application.

Key words: cobalt-doped titanium dioxide, titanium dioxide, photocatalysis, visible light, antibacterial activity