Synthesis, Characterization, and Enriched Photocatalytic Performance of FeS/NiS-Engineered Graphene Oxide (GO) Nanocomposites for Environmental Applications

Iron sulfide (FeS) and nickel sulfide (NiS) nanoparticles were synthesized through coprecipitation and hydrothermal methods, respectively. The nanoparticles were confirmed for the structural and morphological analysis using XRD patterns with crystallite sizes of 29 and 22 nm, respectively. The modified Hummers' method was exploited to synthesize GO nanoflakes with a crystallite size of 13 nm, which was confirmed via XRD and SEM images. FeS/NiS@GO nanocomposite was prepared via the coprecipitation route. The structure and composition were confirmed through FTIR and XRD, with a crystallite size of 30 nm. SEM micrographs depicted the spherical nanoparticles of FeS and NiS, well adhered to the GO nanoflakes, thus providing the extensive surface area responsible for catalytic behavior. The photocatalytic behavior of the nanomaterial was investigated through the degradation studies of Rhodamine B dye. UV–Visible spectroscopy was utilized to monitor the absorbance due to dye molecules at λ_max. The percentage degradation was increased with increased contact time, thus photodegrading the dye molecules. With a contact time of 4.5 h, the degradation of Rhodamine B was observed to reach about 90%. Hence, photocatalytic activity of the newly synthesized nanocomposite, FeS/NiS@GO, presents an efficient class of materials for the treatment of wastewater.