One-pot process for anodic oxide films of titanium with high photocatalytic activity

Abstract

Thick anodic oxide film with high photocatalytic activity was prepared successfully in 1.5 kmol/m 3 H 2SO 4-0.3 kmol/m 3 H 2O 2 with 0.03-0.09 kmol/m 3 H 3PO 4 in a one-pot process. Increasing H 3PO 4 concentration in the range of 0-0.3 kmol/m 3 suppressed spark discharge, resulting in a higher anatase-to-rutile ratio and fewer lower-valent titanium oxides in the anodized films. The photocatalytically active films consisted of a mixture of anatase and rutile crystallites with a small amount of Ti 3+ ions, and had very rough surface with a large number of pores with a diameter on the order of micrometers. The film prepared in the 1.5 kmol/m 3 H 2SO 4-0.3 kmol/m 3 H 2O 2-0.03 kmol/m 3 H 3PO 4 dispersed with TiO 2 nanoparticles was the most active photocatalytically among the films obtained, and exhibited antibacterial activity.