Photocatalytic activity of sol-gel derived titania converted into nanocrystalline powders by supercritical drying

Nanocrystalline (14-18 nm) anatase TiO2 powders with high photocatalytic activity are synthesized by a sol-gel method followed by supercriticall drying in isopropanol. The photocatalytic behavior is studied in the model reaction of phenol photodegradation in water. The relationship between photoactivity, crystal structure, texture, charge-carrier lifetimes, bandgap energies and thermal treatment of products is discussed. The effective method of synthesis of photocatalysts based on TiO2-sol-gel method followed by supercritical drying in isopropanol is presented. It shows, that the obtained powders can be used in photocatalytical depollution without additional thermal treatment. (c) 2004 Elsevier B.V. All rights reserved.