Photocatalytic degradation of azure B under visible light irradi-ation by reduced graphene oxide-NiS composite

Abstract

A composite of reduced graphene oxide (RGO) and nickel sulfide (NiS) was prepared via mecha-nochemical method and further characterized by X-ray diffraction (XRD), Fourier-transform infrared spectroscopy (FTIR) and energy dispersive analysis of X-rays (EDAX). NiS was prepared via precipita-tion method, and RGO was prepared via reduction of graphene oxide. The photocatalytic performances of as prepared RGO/NiS composite, RGO and NiS were evaluated using azure B model system. The compo-site exhibited good photocatalytic activity as compared to NiS as well as RGO. The optimum conditions obtained for the photocatalytic degradation of azure B were the following: pH = 8.0, [Azure B] = 2.0 × 10-5 M, amount of composite = 0.10 g, and light intensity = 50.0 mW·cm-2. The rate of degradation of azure B with the composite was found to be 1.79 × 10-4 s-1.