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

Abstract We examined the partial reduction of anatase-type TiO 2 by argon (Ar) plasma treatment and hydrogen (H 2 ) plasma treatment to investigate the differences in catalyst characteristics in the visible-light region. The partially reduced TiO 2 samples prepared by Ar 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 TiO 2 − x , Ar plasma treatment appears to have an effect similar to that of H 2 plasma treatment with respect to high-discharge input power.