TIO2 AEROGELS FOR PHOTOCATALYTIC DECONTAMINATION OF AQUATIC ENVIRONMENTS

We describe synthesis and applications of nonsupported semiconducting porous structures that can be used as photocatalysts for photodegradat ion of organic pollutants in aqueous environments. The photocatalysts, TiO2 aerogels, are prepared through the sol-gel method and supercriti cal point drying. These materials have a porosity of 85%, a BET surfac e area of 600 m2/g, and a bulk density of 0.5 g/cm3. X-ray diffraction show the anatase crystalline phase with a crystallite size of 50 angs trom. The surface area, pore volume, and pore size distribution of the se materials depend on the preparation conditions. The photoassisted o xidation of salicylic acid on these materials was compared to that obt ained with commercial (P-25) TiO2 powder. The aerogel shows a much hig her photocatalytic activity.