Photochemical Behavior of Ag-0 or Au-0 Decorated Nanostructured TiO2 Prepared by a Facile in Situ Reduction Method

The present work deals with the preparation and photochemical characterization of nanostructured TiO2 samples, decorated with metallic silver (Ag-0) or gold (Au-0), in the form of nanoparticles and/or agglomerates. Specifically, both a commercial TiO2 nanopowder and TiO2 mixed nanoparticles/nanowires (TNNWs), prepared via hydrothermal treatment in alkaline medium, were used as substrates for the growth of metallic Ag and Au species. The preparation route explored the intrinsic properties of the optical semiconductor, generated after lamp photoexcitation. An excess of Ti3+ states were created, in the absence of oxygen and in the presence of both UV light and a HO center dot scavenger. Several spectroscopic techniques were used to characterize the photochemical behavior of all samples and, ultimately, to evaluate the plasmonic response of the materials.