Visible light responses of sulfur-doped rutile titanium dioxide photocatalysts fabricated by anodic oxidation

Anodic oxides on pure titanium provide rutile-structured TiO2 photocatalysts with sub-micron pores. The photocatalysts effectively bleached methylene blue aqueous solution under visible light illumination with wavelengths longer than 413 nm. Auger electron spectroscopy and infrared absorption analyses revealed the presence of sulfur in the anodized oxide. The sulfur doping appears to play an important role in response to visible light by narrowing the band gap of pristine TiO2.