PREPARATION AND UTILIZATION OF ORGANICALLY MODIFIED SILICA-TITANIA PHOTOCATALYSTS FOR DECONTAMINATION OF AQUATIC ENVIRONMENTS

A new class of photocatalysts that can be used for decontamination of aquatic environments from organic and chloroorganic contaminants is re ported. The photocatalysts are comprised of homogeneous dispersion of TiO2 nanocrystals in organically modified SiO2. These composite materi als were prepared by a two-step acid catalyzed sol-gel preparation pro tocol. The combination of the improved photocatalytic activity of homo geneous dispersion of segregated nanocrystalline TiO2 and the adsorpti on properties of organically modified silica increases the rate of dec omposition of hydrophobic organic pollutants in aquatic environments. An additional advantage of these catalysts is their floating capabilit y. This property provides a possibility of using them under solar illu mination. The activity of the organically modified SiO2-TiO2 catalyst is compared with that of commercial nanocrystalline TiO2 and TiO2-SiO2 and TiO2 sol-gel derived xerogels, under solar light and UV lamp irra diation.