Fatemeh Zahra hedayati kaliji - Chemical Engineering Department, Faculty of Engineering, University of Sistan and Baluchestan, Iran
Masoud Shayesteh - Chemical Engineering Department, Faculty of Engineering, University of Sistan and Baluchestan, Iran
Abdolreza Samimi - Chemical Engineering Department, Faculty of Engineering, University of Sistan and Baluchestan, Iran

In this study, effect of calcination temperature on crystal phase and photocatalytic activity of nano-crystal TiO2 was investigated. TiO2 nanoparticles were synthesized using sol-gel technique. They were aggregated into sols, with average colloid size of 36 nm. Samples were then calcinated at three temperatures; 400, 500 and 600 °C for 2 hours. Crystal phase formed in each temperature was characterized by X-ray diffraction (XRD). To investigate the effect of calcination temperature on photocatalytic activity of samples, photo-degradation of methyl orange was measured in aqueous solution using constant initial concentration for all conditions. The results show that the calcination temperature plays an important role in the photocatalytic activity of TiO2. By increasing the calcination temperature, crystal phase of TiO2 changed from anatase to rutile while photocatalytic activity of samples decreased.

TiO2, sol-gel method, calcination, Photocatalytic activity