Ceramics-Silikáty 55 (1) 31-35 (2011)

FACTORS INFLUENCING THE PREPARATION OF TiO2 NANOPOWDERS FROM TITANIA SOL

F. M. K. Tehrani, M. Rashidzadeh, A. Nemati, A. Irandoukht

Titania nanoparticles with high photocatalytic activity were prepared from titanium alkoxide dissolved in alcohol and water under acidic conditions. The effects of the key parameters including (alkoxide/water) ratio, (alkoxide/alcohol) ratio, precursor type, solvent type, type and concentration of stabilizer, calcination temperature, presence of methylcellulose (MC) and hydrothermal treatment were studied. The optimal conditions were obtained through an experimental design technique. This technique is also used to find the main factors influencing the degradation of methylene blue (MB) and mass percent of anatase phase. The powders characteristics were investigated by XRD and Brunauer-Emmett-Teller (BET) methods. The X-ray diffraction studies showed that the product has anatase crystal structure with average particle size below 13 nm. The photocatalytic activities of the TiO₂ nanoparticles were assessed by the degradation of MB in aqueous solution. According to the obtained results, the kinetics of photocatalytic reaction followed pseudo-first-order model. The results showed that the main factors influencing the degradation of MB were the type of stabilizer, presence of MC, hydrothermal treatment, solvent type and calcination temperature. Specific surface areas of the nanoparticles were between 76-198 m²/g.

Keywords: Plakett-Burman Design, Titania, methylene blue, Photocatalyst