Effective photocatalytic degradation of an azo dye over nanosizedAg/AgBr-modified TiO2 loaded on zeolite

摘要

Zeolite-based photocatalysts were prepared by the sol- gel and deposition methods. The photo-catalysts were characterised by X-ray diffraction, nitrogen adsorption- desorption isotherms, FTIR spectroscopy, scanning electron microscopy and energy-dispersive X-ray spectrometry. The activity of the prepared photocatalysts was evaluated by the UV-induced degradation of acid blue 92, a textile dye in common use. The effect of various parameters, such as catalyst concentration, initial dye concentration, thiosulphate concentration and pH, on the rate and efficiency of the photocatalytic degradation of acid blue 92 was investigated. The results showed that each parameter influenced the degradation rate and efficiency in a particular way. It was also found that, under optimised conditions, Ag/AgBr/TiO_2/zeolite exhibited the highest photocatalytic performance. A comparison of catalytic activity when exposed to visible light under the same conditions showed that the photocatalysts containing AgBr had the highest activity.