Green synthesis of Au/TiO2 for effective dye degradation in aqueous system

Abstract

Nanocomposites of Au/TiO2 were prepared by green synthesis method using the aqueous extract of Cinnamomum tamala leaves as the reductant The structural and morphological properties of the nanocomposites were studied by X-ray diffraction, UV-visible diffuse reflectance, FT-IR and transmission electron microscope. XRD and TEM analysis exhibits the formation of well dispersed gold nanoparticles on the surface of titania. The photocatalytic activity of the catalysts prepared by green method was evaluated for the degradation of methyl orange as a model reaction. It was found that the catalysts modified with 2 wt% gold (2Au/TiO2-9-2) exhibits 2.5 times higher degradation activity towards methyl orange dye compared to Degussa P-25 TiO2 under solar light irradiation. Effect of parameters such as pH and plant extract concentration has been evaluated on the morphology of gold nanoparticles and photocatalytic degradation of MO. The dye degradation rate followed first order kinetics. (C) 2013 Elsevier B.V. All rights reserved.