Vapor-thermal preparation of highly crystallized TiO2 powder and its photocatalytic activity

Nanocrystalline anatase TiO2 powder photocatalysts were synthesized by a vapor-thermal method using tetrabutyl titanate as precursor at a temperature range from 120 to 200 degrees C. The as-synthesized products were characterized by X-ray diffraction, N-2 adsorption-desorption measurement, transmission electron microscopy, high resolution transmission electron microscopy, Fourier transform infrared spectra, Raman spectra, and their photocatalytic activity was evaluated by photocatalytic oxidation decomposition of acetone in air. The results showed that reaction temperature greatly affected the microstructures and photocatalytic activity of the samples. With increasing reaction temperature and time, the average crystalline size of TiO2 particles increased and their crystallization enhanced, while the specific surface area of the products decreased. The TiO2 powders obtained at a temperature range from 150 to 200 degrees C for 10h showed good photocatalytic activity and were greatly higher than that of Degussa P-25. (c) 2007 Elsevier Inc. All rights reserved.