Fe3+:Ag/TiO2 nanocomposite: Synthesis, characterization and photocatalytic activity under UV and visible light irradiation

A facile wet impregnation/photo-deposition method was performed to prepare a promising Fe3+:Ag/TiO2 nanocatalyst with high photocatalytic activity under ultraviolet and visible light irradiation. The nanophotocatalyst was characterized by X-ray diffraction, field emission scanning electron microscopy, transmission electron microscopy, energy-dispersive spectroscopy, inductively coupled plasma optical emission spectroscopy, X-ray photoelectron spectroscopy and UV-visible absorption spectroscopy. The photocatalytic efficiency of the prepared catalyst was evaluated through using the decomposition of Methylene Blue as a model compound under different light irradiations. Four light filters with various transmittance wavelengths were also applied to evaluate the probable photodegradation mechanism. Total organic carbon (TOC) was measured in order to evaluate the dye degradation. XPS spectra confirmed Fe(III) ions doped into TiO2 structure while silver nanoparticles deposited on the TiO2 surface. Fe3+ and Ag have synergistically improved the photocatalytic activity of TiO2 for photodegradation of dye under both ultraviolet and visible light irradiation. The co-operation of Fe3+ and Ag in the narrowing of the band gap and promoting the separation of the photogenerated electron-hole pairs was confirmed by photoluminescence spectroscopy. An appropriate Fe(III) and Ag ratio in the nanocomposite is found to be beneficial for the synergistic effect of doped metal ion and deposited noble metal nanoparticle. Fe3+:Ag/TiO2 nanocatalyst exhibits the potential to be effective in wastewater treatments superior to bare TiO2. (C) 2014 Elsevier B.V. All rights reserved.