Tóm tắt

In this research work, metallic gold nanoparticles with optimal concentration 6.7 u000110rn17atom/mrn2rnillus-trates an exceptional photocatalytic reactivity in removal of methylene blue and indigo carmine dyes onrntitania surface. Titania nanoparticles were fabricated by sol-gel method and Au nanoparticles were incor-porated by incipient wetness route on titania surface without using reducing agent. Various developedrntechniques as XRD, N2-adsorption-desorption isotherm, DRS, PL and HRTEM are selected for studyingrnthe physicochemical properties of the hybrid nanoparticles. The photocatalytic efficiency of the as-synthesized nanoparticles was estimated and the results reflect that the photocatalytic activity inrnremoval of MB and IC dyes increases with increasing Au concentration and maximizes at 1 wt% followedrnby remarkable reduction in the photoreactivity monotonically. The photocatalytic rate constant inrnremoval of MB dye is 0.069 minrnu00031rnwhich is fifty times than that of titania single phase (0.0014 minrnu00031rn).rnThe point of zero charge of Au/TiO2estimated from zeta potential measurement is 8.4 reflecting the facil-ity of removal of IC dye compared with MB dye. The electron transfer from titania conduction band to AurnFermi level is primary cause for enhancing the quantum efficiency of the photogenerated charge carriers.rnHydroxyl radical and positive hole are the main reactive species in removal of MB dye on gold doped tita-nia. The photocatalytic stability implies the strong catalytic performance of the prepared nanoparticlesrnafter five consecutive cycles