Enhanced Raman scattering and photocatalytic activity of TiO sub(2) films with embedded Ag nanoparticles deposited by magnetron sputtering

Nanoaprticles(Nps)-Ag/TiO sub(2) multilayer films with different working pressures of Ag and inserted SiO sub(2) shell layers between Ag and TiO sub(2) were prepared by alternate magnetron sputtering. The formation of Ag nanoparticles embedded in TiO sub(2) 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 TiO sub(2) film, the Nps-Ag/TiO sub(2) and Nps-Ag/SiO sub(2)/TiO sub(2) 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/TiO sub(2) film is related with the improved charge separation by the embedded Ag nanoparticles.