Sol-gel Preparation of Different Crystalline Phases of TiO₂ Nanoparticles for Photocatalytic Degradation of Methylene Blue in Aqueous Solution

This paper describes the photocatalytic degradation of methylene blue (MB) in aqueous solution in the presence of TiO2 nanoparticles (NPs) in different compositions of anatase and rutile phases under UV light irradiation. The different compositions of crystalline phases of TiO2 NPs were synthesized using sol-gel method at the same temperature for various calcination times. The TiO2 NPs were subjected to crystal phase, vibrational, size, and morphological characterizations. The photocatalytic degradation of MB revealed that anatase TiO2 NPs have a superior catalytic activity in the front of rutile phase. This finding further suggested that low charge resistance and low electron-hole recombination probability lead to the acceleration of the OH？ formation on the surface of anatase TiO2 NPs