Synthesis of size-controlled silica-supported TiO2 photocatalysts

Supported nanocrystalline titanium dioxide has been prepared by a sot-gel method through the use of mesoporous silica materials. The work has been addressed to study the effect of the different type of silica support on the mean titania particle size and their effect in the photocatalytic activity. The prepared samples have been characterised by powder X-ray diffraction (XRD), nitrogen adsorption. UV-VIS spectroscopy, EDS, and TEM and their photocatalytic activity has been checked for cyanide oxidation in liquid phase. A correlation between the textural properties of the chosen silica support and the diameter of the obtained titania particles is observed. The use of mesostructured SBA-15 silica support with a pore diameter around 7 nm has shown to be an effective method to obtain photocatalysts with controlled TiO2 particle size even at high semiconductor contents (up to 60 wt.%). (C) 2002 Elsevier Science B.V. All rights reserved.