Anatase TiO₂ co-doped with silver and ceria for antibacterial application

Anatase TiO₂ co-doped with Ag and CeO₂ (Ag/CeO₂-TiO₂) was prepared by the peroxo sol-gel method for antibacterial application. The as-prepared materials were characterised by high resolution transmission electron microscopy (HRTEM), X-ray diffraction (XRD), scanning electron microscopy (SEM) and X-ray photoelectron spectroscopy (XPS). The antibacterial activities of the samples were tested against two different bacteria: Escherichia coli (OP50), a Gram-negative organism and Staphylococcus aureus (USA300), a Gram-positive organism. The antibacterial effectiveness of the Ag/CeO₂-TiO₂ coating was >99.99%, i.e. it was extremely effective against both E. coli (OP50) and S. aureus (USA300) after either 30 min of illumination with UVA radiation or 24-h of incubation in the dark. The Ag/CeO₂-TiO₂ coating was found to be significantly more active than pure TiO₂ and TiO₂ doped with CeO₂ or Ag alone. Therefore, Ag/CeO₂-TiO₂ can be used as a coating material for the disinfection of both Gram-positive and Gram-negative bacteria.