Photodegradation of toluene using silica-embedded titania

Silica-embedded titania photocatalyst was prepared by the sol–gel technique. The prepared samples have been characterised by powder X-ray diffraction (XRD), nitrogen adsorption, FT-IR spectroscopy, and TEM. From the results of XRD and FT-IR spectra, the prepared silica-embedded titania had the structure of amorphous silica embedded into an anatase titania matrix. The embedding of amorphous silica into nanophase titania matrix helped to increase the thermal stability of titania and suppressed the transformation of anatase into rutile and made it possible to calcine the silica/titania particles at higher calcination temperatures. Addition of silica has further resulted in considerable increase of anatase–rutile transformation temperature >800 °C. Therefore, we concluded that the high-temperature stability of anatase resulted from the mixture of titania ans silica. The effect of the amount of SiO2 loading on nanosized TiO2 support on the photodecomposition of toluene was studied. The pure titania showed lower activities than the SiO2-loaded titania for photodegradation of toluene. The role of the silica support in the photodecomposition of toluene was discussed as well.