The generation of TiO2 nanoparticles by the thermal decomposition of titanium tetraisopropoxide (Trip) was carried out experimentally using a tubular electric furnace at various synthesis temperatures (700-1300 degrees C) and TTIP heating temperatures (80-110 degrees C). The photocatalytic activity of the resulting TiO2 nanoparticles was examined by measuring the rate of methylene blue decomposition. The TiO2 nanoparticles were characterized by X-ray diffraction (XRD), Brunauer-Emmett-Teller (BET) measurements and transmission electron microscopy (TEM). The crystallite size and crystallinity increased with increasing synthesis temperature and TTIP heating temperature. A TTIP heating temperature and synthesis temperature of 95 degrees C and 900 degrees C, respectively, were found to be the optimal synthesis conditions. The primary particle diameter obtained under optimum synthesis conditions was considerably smaller than the commercial photocatalyst (Degussa, P25). The specific surface areas were more than 134.4 m(2) g(-1). Under the optimal conditions, the photocatalytic activity for methylene blue was higher than that of the commercial photocatalyst. (C) 2010 Elsevier B.V. All rights reserved.