Photo-switchable pure water splitting under visible light over nano-Pt@P25 by recycling scattered photons

Visible light absorption peak from near-field dielectric scattering was observed in case of Pt nanoparticles directly supported on P25. This absorbed scattered light could drive visible-light photocatalytic pure water splitting (lambda > 420 nm). It is interesting that the roles of Pt and P25 in photocatalytic hydrogen generation were switchable under different irradiation conditions. Under UV-vis irradiation, P25 represented a photocatalyst while Pt was cocatalyst. Under visible light irradiation (lambda > 420 nm), Pt would prefer to act as a photocatalyst while P25 was analogous to cocatalyst. Moreover, defects (Ti3+ or V-o) on the surface of Pt/P25 would be generated under UV irradiation. These defects are similar with a sacrificial agent to consume photogenerated holes, which are necessary for visible-light-drive photocatalytic pure water splitting.