Photocatalytic Mineralization of Methylene BlueAqueous Solutions by Ag/TiO2 Nano Composite

Abstract

Nanocomposite of Ag/TiO2 and nanocrystalline TiO2 were prepared by using TiCl4 as a precursor in a simple sol-gel process. The prepared photo-catalysts were characterized by X-ray diffraction (XRD), scanning electron micrographs (SEM), energy dispersive X-ray microanalysis (EDX), transmission electron microscopy (TEM) and diffuse reflectance spectroscopy (DRS). A complete and effective photocatalytic degradation of a cationic aromatic dye, Methylene blue, in aqueous solutions has been carried out using nanocomposite of Ag/TiO2 and nanocrystalline TiO2 under UV-C light irradiation. Experiments were conducted to compare the photocatalytic activities of nanocomposite Ag/TiO2 with nanocrystalline TiO2 . The photoreactions were followed by monitoring the degradation of the dye as a function of irradiation time, in the presence of the nanophoto-catalysts, by the visible/ultraviolet absorption spectroscopy. It has been found that the presence of silver in TiO2 nanoparticles reduces the duration of complete photocatalytic degradation of Methylene blue by 20% due to the enhancement of electron-hole separation by the electron trapping of silver particles.