Synthesis of mesoporous TiO2-SiO2-Ag and investigation of its structural and photocatalytic properties under visible light and ultra-violate

In this project, mesoporous titanium oxide-silicon oxide doped by silver (TiO2-SiO2-Ag) was hydrothermally synthesized. Titanium isopropoxide, tetraethyl orthosilicate and silver nitrate were used as precursors for TiO2, SiO2 and Ag, respectively. Initially TiO2-SiO2 mesoporous nanocomposite was synthesized with weight ratios of silica to titania SiO2:TiO2:3:1 via hydrothermal method at 70˚C and 130˚C, then 5wt% of silver was added to each sample. The samples were characterized using XRD, SEM, EDS, Map and BET analysis and photocatalytic performance of synthetic samples under visible light and ultra-violate were investigated using UV-Vis spectroscopy The results of isotherm adsorption-desorption of nitrogen indicate the mesoporous structure of TiO2-SiO2 samples. XRD analysis confirmed the presence of anatase and rutile phases in TiO2-SiO2 samples and also the presence of silver phase along with anatase and rutile in TiO2-SiO2-Ag composition. Examination of the photocatalytic activity of the specimens by visible and ultraviolet light showed that the highest degradation percentage of pollutant (33%) under visible-light and ultra-violate was observed for the sample with silica to titania ratio of 3 via hydrothermal method at 70˚C with additions of silver during synthesis (TS3A-70).