SOL-GEL DERIVED ANATASE TIO2 - MORPHOLOGY AND PHOTOACTIVITY

High-surface area TiO2 (anatase) was prepared by the sol-gel method and characterized by various instrumental and analytical methods, including X-ray diffraction, thermogravimetric analysis, infrared spectroscopy, porosimetry, specific surface area measurements, scanning electron microscopy, and titration of surface hydroxyl groups. The specimen was tested for photodegradation of phenol and nitrophenols carried out in aqueous suspension at pH=3; photoactivity was compared with that of commercially available anatase TiO2. Results are discussed in terms of porosity, surface area, and availability and population of surface OH groups, consequent upon the particular method used for preparation. The observed partial deactivation in time of gel-derived anatase was studied, and almost complete restoration of photoactivity after thermal treatment at 573 K for 3 hours was observed.