A Comparasion of Photocatalytic Activity Between FeS2, Ni-Doped FeS2Nanoparticles and Un-Doped FeS2/rGO Composite

Un-doped and Ni-doped FeS(2)nanoparticles (NPs) with a doping concentration of 4.0 at.% have been synthesized by a solvothermal method. The obtained materials have been characterized by means of XRD, SEM, BET, Raman and UV-VIS spectroscopy. The photocatalytic activity has been evaluated based on degrading methylene blue with thin films of the NPs under UV-VIS light irradiation. An important observation was that the activity increases in the sequence FeS(2)NPs -> Ni-doped FeS(2)NPs -> composite of FeS(2)NPs/rGO. The enhanced energy gap and enlarged surface area, achieved by the Ni-doping and adding rGO were considered to be the main reason for the improved photocatalytic activity. Additionally, the mechanism of degradation has been studied using several scavengers. The photo-generated center dot OH and center dot O-2(-) have shown to be dominant radicals in the visible light MB degradation. The presented data strongly suggest that the composite of FeS(2)NPs/rGO may be an efficient heterogeneous photo-catalyst for the degradation of the organic contaminant and water treatment. The proposed film forms of materials are promising for convenient reuse after a low-cost cleaning.