A visible-light active TiO2 photocatalyst multilayered with WO3

Abstract

Sputter-deposited TiO₂ films with high visible-light photocatalytic activity were successfully realized by a hybrid TiO₂/Pt/WO₃ film structure with Pt nanoparticles uniformly distributed at the interface of the TiO₂ and WO₃ films. The TiO₂/Pt/WO₃ hybrid films enable the complete decomposition of CH₃CHO under visible-light irradiation. The water contact angle of the TiO₂/Pt/WO₃ 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 WO₃ are transferred to the surface of the TiO₂ 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.