Preparation, characterization and photocatalytic activity of TiO2 towards methylene blue degradation

Titanium dioxide (TiO2) powders were prepared by simple hydrolysis of titanium tetrachloride (TiCl4) followed by subsequent drying at 100 °C. The as prepared powders were calcined at different temperatures ranging from 400 to 900 °C. The as synthesized as well as calcined TiO2 powders were characterized using X-ray diffractometry, scanning electron microscopy and BET surface area measurements. X-ray diffractometry revealed anatase to rutile phase transformation above 800 °C for the TiO2 powders. Photocatalytic activity of these samples was evaluated by studying the degradation of 10 ppm aqueous methylene blue dye under 400 W high pressure mercury vapor lamp with 50 mg of TiO2 powders. Highest photocatalytic activity was observed for TiO2 powder calcined at 750 °C due to presence of anatase and rutile phases in 80:20 ratio. The activity of powder calcined at 750 °C was comparable with commercial Degussa P-25 TiO2 powders owing to similar phase composition.