A visible-light active TiO photocatalyst multilayered with WO.

Sputter-deposited TiO films with high visible-light photocatalytic activity were successfully realized by a hybrid TiO/Pt/WO film structure with Pt nanoparticles uniformly distributed at the interface of the TiO and WO films. The TiO/Pt/WO hybrid films enable the complete decomposition of CHCHO under visible-light irradiation. The water contact angle of the TiO/Pt/WO hybrid films reaches below 5° under visible-light irradiation. Pt nanoparticles are considered to act as a cocatalyst to improve the electron-hole separation efficiency. We demonstrate that the photogenerated holes in WO are transferred to the surface of the TiO film with less hole-trapping and induce high visible-light photocatalytic activity and hydrophilic behavior, and the photogenerated electrons are accumulated in the Pt nanoparticles. The highly hydrophilic thin films with high visible-light photocatalytic activity can be applied to various indoor products possessing self-cleaning and antifogging properties.