Photoinduced Electron Storage and Surface Plasmon Modulation in Ag@TiO2 Clusters

Abstract

The reversible charging and discharging effects associated with photoexcitation of a TiO₂ shell in a [email protected]₂ composite are described. The photoinduced charge separation in the TiO₂ shell is followed by electron injection into the silver core. Interestingly, the charging of the silver core is associated with the shift in the surface plasmon band from 460 to 430 nm. The stored electrons are discharged upon exposure of the charged [email protected]₂ composite to an electron acceptor. As the electrons from the silver core are discharged, the original surface plasmon absorption of the Ag core is restored.