Synthesis and characterization of Ag nanoparticles and Ag-loaded TiO2 photocatalysts

Abstract

Ag nanoparticles and Ag–TiO2 nanostructures were grown on (001) SiO2 quartz substrates by pulsed laser deposition using a KrF* excimer laser source (λ = 248 nm, τFWHM~10 ns, ν = 10 Hz) for the irradiation of Ag and TiO2 targets. The obtained structures were characterized by atomic force microscopy, X-ray diffraction, X-ray photoelectron spectroscopy, and UV-visible absorption spectroscopy. Photocatalytic activity was evaluated under near-UV light illumination by decomposition of methylene blue. The relationship between the laser synthesis process parameters and nanoparticles’ chemical composition, crystal structure, morphology, shape and size distribution on the substrate surface were investigated and correlated with their optical properties. The established experimental parameters were used for the synthesis of nanostructures consisting of anatase phase TiO2 thin films covered by Ag nanoparticles for photocatalytic applications. The optimum experimental conditions were determined which ensure significantly improved photoactivity in the presence of Ag nanoparticles as compared to the bare oxide surface.