SY N THESIS AND CHARACTERIZATION OF TiO 2 NANOCRYSTALS BY SOL - GEL METHOD AND STUDY THE EFFECT OF CALCINATION TEMPERATURE ON ITS PHOTOCATALY TIC ACTIVIT

TiO 2 nano part i cles w ere prepared by a simple s ol - gel method at different calcinations temperature . The prepared samples were characterized by X - ray diffraction and UV visible spectroscopy tech niques . H ydroxyl radicals (?OH) formation on the TiO 2 surface underUV light was detected by UV visible absorption spectroscopic technique. The photocatalytic activity was evaluated by photocatalytic de grada tion of Methelene Blue ( M B) aqueous solution under UV light exposour . The results revealed that the TiO 2 could be crystallized via s ol - gel method. The absorption of light, the development rate of hydroxyl radicals, and photocatalytic de grada tion of M B aqueous solution were significantly improved for mixed phase instead of simple anatase or rutile phase .