Antibacterial properties of silver-doped TiO2 nanoparticles under solar simulated light

Ag-doped TiO2 nanoparticles were synthesized by combination of two bottom-up and top-down methods and the products were characterized by X-Ray diffraction (XRD), Brunauer Emmett Teller (BET), X-ray photoelectron spectroscopy (XPS) and ultra violet-visible absorption spectroscopy (UV-Vis). The visible light antibacterial activities were successfully demonstrated for the inactivation of Escherichia coli (E-coli) bacteria. The results revealed that the Ag/TiO2 nanoparticles extended the light absorption spectrum toward the visible region and significantly enhanced the inactivation of E-coli bacteria under visible light irradiation. 0.15 g Ag/TiO2 nanoparticles exhibited highest antibacterial activity. The significant enhancement in the antibacterial properties of Ag/TiO2 nanoparticles under visible light irradiation can be ascribed to the effect of doped noble metal Ag by acting as electron traps in TiO2 band gap.