Photocatalytic activity, antibacterial effect and photoinduced hydrophilicity of TiO₂ films coated on stainless steel substrate

Transparent TiO₂ films on stainless steel prepared by dip coating in a nonionic microemulsions solution have been shown to have much higher photocatalytic activity than those coatings on glass. Fe³⁺ and Fe²⁺ ions, diffusing from stainless steel substrate into TiO₂ films during high-temperature calcination, behave as dopants to significantly affect the films' photocatalytic activity. An optimum calcination condition, under which the amount of diffused Fe³⁺ and the ratio of Fe³⁺ to Fe²⁺ ions favor the film's photocatalytic reaction, was obtained. In addition, this TiO₂ films also exhibits excellent photoinduced hydrophilicity and antibacterial effect for the sterilization of Bacillus pumilus. As stainless steel is a very common material, practical systems for pollution treatment and disinfection may be designed based on this enhanced coating. Copyright © 2003 American Chemical Society.