Enhanced Raman scattering and photocatalytic activity of TiO2 films with embedded Ag nanoparticles deposited by magnetron sputtering

Nanoaprticles(Nps)-Ag/TiO2 multilayer films with different working pressures of Ag and inserted SiO2 shell layers between Ag and TiO2 were prepared by alternate magnetron sputtering. The formation of Ag nanoparticles embedded in TiO2 matrix was confirmed by the XRD and TEM results. The optical absorption peaks assigned to the surface plasmon resonance (SPR) of Ag nanoparticles were observed in the wavelength range of 550-750 nm. With increasing working pressure of Ag, the SPR peaks show blue-shift due to the decreasing Ag Nps size and increasing spacing between them. Compared with the pure TiO2 film, the Nps-Ag/TiO2 and Nps-Ag/SiO2/TiO2 film show significantly enhanced Raman scattering due to the strong local field induced by the SPR of Ag nanoparticles, and the enhanced photocatalytic activity of Nps-Ag/TiO2 film is related with the improved charge separation by the embedded Ag nanoparticles. (C) 2016 Elsevier B.V. All rights reserved.