Preparation and characterization of nano titanium dioxide photocatalysts via sol gel method over narrow ranges of varying parameters

Abstract

The present study addresses a tailored preparation method of different structures of TiO2 nanoparticles over narrow ranges of varying parameters. In this work, titanium-n-butoxide was used to prepare TiO2 nanoparticles via sol gel method. The influence of the experimental preparation conditions: pH, drying and calcination temperatures were studied at ranges 5-9, 70-110°C, and 450-650°C, respectively. Slight changes through these mentioned ranges lead to drastically change in the phase transformation, degrees of crystallinity and crystal systems of the prepared TiO2. Pure anatase and rutile forms as well as different ratios of mixed phases were obtained. X-ray diffraction and transmitting electron microscope TEM techniques were used for the characterization of the prepared samples. The photocatalytic performance of TiO2 samples were evaluated according to their abilities toward the generation of the highly active hydroxyl radicals. Results indicate that the photocatalytic activities of TiO2 samples are dependent on their preparation experimental conditions. The maximal photocatalytic activities were noticed at high pH and drying temperature values.