Visible-light photocatalytic activity of anatase TiO2 treated with argon plasma

We examined the partial reduction of anatase-type TiO2 by argon (At) plasma treatment and hydrogen (HA plasma treatment to investigate the differences in catalyst characteristics in the visible-light region. The partially reduced TiO2 samples prepared by At plasma treatment and H-2 plasma treatment gave broader, red-shifted absorption bands in the visible-light region and showed evidence of visible-light absorption due to oxygen defects. For the visible-light photocatalytic activity of TiO2-x, Ar plasma treatment appears to have an effect similar to that of H-2 plasma treatment with respect to high-discharge input power. (C) 2009 Elsevier B.V. All rights reserved.