Physicochemical properties and photocatalytic activity of the TiO2/SiO2 prepared by precipitation method

Low cost, highly active TiO2/SiO2 catalysts have been prepared using TiOSO4·2H2O and SiO2 sol by a precipitation method. Among the catalysts, the TiO2/SiO2 complex containing 5 wt.% of SiO2 and calcined at 650 °C, presents the highest photocatalytic activity. The conversion of benzene on the TiO2/SiO2 sample is 63% higher than it was presented by the un-doped TiO2. Ti–O–Si bond in the TiO2/SiO2 samples, containing SiO2 both 7.5 wt.% and 10 wt.%, was observed from FT-IR spectroscopy, even though the TiO2/SiO2 samples were prepared by an inorganic synthesized route from TiOSO4 and SiO2 sol. XRD, BET, and NH3-TPD reveal that the crystal size of catalysts decreases, the surface area increases, and the amounts of total acidic sites go up when the silica is doped into the TiO2 photocatalysts. The photocatalytic activity of the TiO2/SiO2 prepared is mostly attributed to their high surface area, large pore volume, large surface acidity, and more surface hydroxyl groups.

FT-IR spectra of TiO2/SiO2 samples with different SiO2 doping amounts, calcined at 650 °C.Figure optionsDownload as PowerPoint slideHighlights
► TiOSO4 and SiO2 aqueous sol as TiO2/SiO2 catalysts precursors, low cost.
► Ti–O–Si bond was observed from FT-IR, even though by an inorganic synthesized route.
► Preparation process facile to realize industrial scale, safe and no pollution.