Preparation of the xerogels of nanocrystalline titanias by the removal of the glycol at the reaction temperature after the glycothermal method and their enhanced photocatalytic activities

Xerogels consisting of nanocrystalline silica-modified titanias were obtained by the reaction of titanium tetraisopropoxide and tetraethyl orthosilicate in 1,4-butanediol at 300 degreesC for 2 h in an autoclave, followed by the removal of the organic phase from the autoclave at the reaction temperature. The coagulation of the ultrafine particles due to the surface tension of the liquid between the particles in the drying stage was prevented, which contributes to the superior thermal stability and photocatalytic activity of the products.