Photocatalytic and Escherichia antibacterial activities of Ag-TiO2-SiO2 nanocomposite powder under simulated solar light irradiation

Abstract

The photocatalytic nanocomposite powder TiO2, TiO2-SiO2 and Ag-TiO2-SiO2 (ATS) were synthesized by sol-gel method assisted with hydrothermal treatment and characterized by X-ray diffraction (XRD), Raman spectroscopy (RAMAN), Fourier transformed infrared spectroscopy (FT-IR), Energy dispersive X-ray (EDX), Transmission electron microscope (TEM), Brunauer-Emmett-Teller (BET) surface area and UV-Vis absorption spectra analysis. The Escherichia coli (E. coli) antibacterial activity of synthesized photo-catalysts under simulated solar light have been also investigated. The heterogeneous A4TS10 with the 4 wt.% Ag and 10 wt.% SiO2 had anatase and rutile phase, spherical in shape with the particle size about 20 – 30 nm, specific surface area (SSA) of 218.4 m2/g, the band gap of 3.06 eV. The E. coli antibacterial activities of the synthesized samples under simulated solar light were also investigated under simulated solar light with 25 W of light intensity. The E. coli antibacterial ability of A4TS10 performed the highest photo-activity. E. coli bacteria was entirely killed after 30-minute irradiation and no bacterial regrowth was observed after 24 hours. The research results demonstrated that the photocatalytic A4TS10 is a promising green material to treatment wastewater infected bacteria application.