Degradation of malachite green oxalate by UV and visible lights irradiation using Pt/TiO2/SiO2 nanophotocatalyst

Titania sol was modified with SiO2 and platinum ion to prepare TiO2/SiO2, Pt/TiO2 and Pt-TiO2/SiO2 nano-photocatalysts. The samples were characterized by means of UV-visible Diffuse Reflectance Spectroscopy (DRS), X-ray Diffraction (XRD) patterns, Scanning Electron Microscopy (SEM) and Transition Electron Microscopy (TEM) images, Energy Dispersive X-ray spectroscopy (EDX) and Brunauer-Emmett-Teller (BET) techniques. The prepared catalysts exhibited photocatalytic activity for degradation of malachite oxalate green (MG) in water under UV light irradiation. BET analysis confirmed a significant increase in surface area, which enhanced photocatalytic activity. In comparison with anatase TiO2 nanoparticles and the commercial Degussa P-25, the prepared photocatalysts showed an improved photoactivity in comparison with anatase TiO2 nanoparticles and the commercial Degussa P-25. The results show that the reduced form of platinum deposited is important for modifying TiO2/SiO2 to be able to operate as a photocatalyst under visible light irradiation. (C) 2011 Sharif University of Technology. Production and hosting by Elsevier B.V. All rights reserved.