Photocatalytic degradation of an acidic dye and a basic dye using heterostructured photocatalyst

Abstract

Most of the natural resources of drinking water are found to be contaminated with various toxic materials. One of the most relevant pollutants is organic dyes. Photocatalysis is a promising green technology for the removal of dyes. In the present work heterostructured NiO/ZnO nanocomposite was prepared using co–precipitation method, analyzed using XRD, SEM and UV/Vis spectroscopy. For comparison purpose NiO was also prepared. Comparison of XRD’s of metal oxides with JCPDS confirmed the formation of heterojunctions. UV/Vis absorption studies confirmed the shift of the optical absorption towards the visible region. The photocatalytic degradations of dyes namely Malachite Green, a basic and Congo Red, an acidic dye were carried out using the prepared composite. Factors affecting photocatalytic degradation like effect of contact time, amount of photocatalyst and dye concentration were also investigated. Results suggested an increase in degradation efficiency in the case of heterojunctions nanocomposite as compared to individual metal oxide.