Photocatalytic activity of Ag nanoparticle-dispersed N-TiO2 nanofilms prepared by magnetron sputtering

Using magnetron sputtering, pure TiO2 nanofilms and Ag/TiO2 bilayer nanofilms doped with nitrogen were deposited on glass substrates. Heat treatment of the Ag/ N-TiO2 nanofilms at 400 degrees C led to the formation of Ag nanoparticles, which were dispersed inside the TiO2 films as well as on the free surface of the TiO2 films. The photocatalytic activity of the Ag/ N-TiO2 nanofilms with dispersed Ag nanoparticles was examined by UV-vis diffuse reflectance spectroscopy. The rate constants for the photodegradation of methylene blue (MB) in aqueous solutions of MB by N-TiO2-based nanofilms are about one order larger than those for self-degradation or for pure TiO2 nanofilms. The rate constants for the photodegradation of aqueous solutions of MB by the Ag/ N-TiO2 nanofilms are larger than those for the N-TiO2 nanofilms. The Ag nanoparticles improve the photocatalytic activity of TiO2 films, possibly through the surface plasmon absorption effect of Ag nanoparticles, which activates photo-generated charge carriers through the transfer of plasmonic energy.