Visible active silver sensitized vanadium titanium mixed metal oxide photocatalyst nanoparticles through sol-gel technique

Silver sensitized titanium vanadium mixed metal (Ag/TiV) oxides were prepared by nanoscale synthesis route employing the sol-gel technique. It led to the development of 5-20 nm particles with predominantly anatase phase. The physicochemical characterization of the particles was done by X-ray diffractrometry (XRD), scanning electron microscopy (SEM), high resolution transmission electron microscopy (HR-TEM), energy dispersive X-ray analysis (EDX), X-ray photoelectron spectroscopy (XPS), UV-visible diffuse reflectance spectroscopy (UV-Vis DRS) and photoluminescence spectroscopy (PL). The reflectance spectrum shows a red shift in the optical response of the catalyst with its band gap absorption upper limit covering a large portion of the visible spectrum, i.e. lambda(abs) >= 700 nm. The performance of the materials was examined under laboratory visible light and solar radiation exposure. The rate of degradation of methylene blue (MB) and phenol exhibited an increase of about six and four times, respectively, in visible light compared to Degussa P-25. This may be attributed to the increased absorption due to Ti-V mixed metal oxides, favorable electron transfer in the anatase-rutile mixed phase coupled with silver's scavenging action and reduced electron-hole recombination thereon. (C) 2010 Elsevier B.V. All rights reserved.