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 degrees C. The as prepared powders were calcined at different temperatures ranging from 400 to 900 degrees 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 degrees 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 degrees C due to presence of anatase and rutile phases in 80:20 ratio. The activity of powder calcined at 750 degrees C was comparable with commercial Degussa P-25 TiO2 powders owing to similar phase composition. (C) 2009 Elsevier B.V. All rights reserved.