Photocatalytic degradation of methyl orange and real wastewater by silver doped mesoporous TiO2 catalysts

Abstract

Abstract The photocatalytic activity of silver doped mesoporous TiO 2 catalysts was evaluated for water treatment. Doped catalysts were prepared by impregnation-reduction with citrate using various Ag loadings (0.5 wt%, 1.5 wt% and 3 wt%) and characterized by X-Ray powder diffraction (XRD), BET and diffuse reflectance UV–vis spectroscopy (DR/UV–vis). Silver doped TiO 2 catalysts retain the physical properties of mesoporous TiO 2 and its hexagonal order. The degradation of methyl orange (MO) as a model organic pollutant and of a real wastewater effluent was carried out under UVC, UVB, UVA and simulated solar light irradiation. Mesoporous TiO 2 showed a better activity than P25 TiO 2 and photocatalytic performance of silver doped mesoporous TiO 2 was enhanced compare to undoped. The mineralization of the organic pollutant was investigated by total organic carbon (TOC) measurements. The 0.5 wt%Ag/TiO 2 exhibited the highest TOC abatement both for the mineralization of MO and of real wastewater under UV and simulated solar light. Moreover, the catalyst was stable and could be used repeatedly. Therefore, this catalyst is promising for photocatalytic wastewater treatment under solar irradiation, leading to a cheap technology for developing countries.