| dc.description.abstract | TiO2 is a photocatalys that can degrade harmful organic compounds into H2O and CO2. In this study, TiO2 sol was prepared by sol-gel method using TiCl4 as precursor and H2O2 as peptizing agent in order to induce the formation of TiO2 nanoparticles that converted from Ti(OH)4 under 95°C. In order to find an efficient way to improve the activity of photocatalyst and antibacterial property, silver was added. SiO2 was then added in the silver-titanium dioxide sol to improve the transmittance of the sol.
The purpose of this study was to apply a sol-gel method to prepare silver modified SiO2/TiO2 to enhance stability of sol, TiO2 particle size distribution, and improve photocatalytic activity under UV light and visible light irradiation. The presence of silver lead to high antibacterial capability. The nanoparticles were characterized by X–ray diffraction (XRD), transmission electron microscopy (TEM), high resolution transmission electron microscopy (HR–TEM), scanning electron microscope (SEM), X–ray photoelectron spectroscopy (XPS), dynamic light scattering (DLS), and UV-Vis spectroscopy. Titanium dioxide sols were anatase as confirmed by XRD and HRTEM. The particle size of the smaple was measured by DLS and HRTEM. Both the sols and the films of titania-silica and silver-titania-silica were active for methylene blue destruction under UV light and visible light irradiation. The results showed that the quantum efficiency of silver-titania-silica was higher than that of titania-silica. The addition of silver could improve the phtocatalytic activity. In addition, the sols remained neutral, stable and did not separate after storage for over a year. The optimum SiO2/TiO2/silver molar ratios were 5/1/0.02, and it showed high photocatalytic activities under both of UV light and visible light irradiation. From antibacteria test, it showed that after irradiation by UVA light for 3 hours, the silver-titania-silica had a high antibacterial ability, and the antibacteria rate reached over 99.9%. | en_US |