Palladium-decorated zinc sulfide/reduced graphene oxide nanocomposites for enhanced visible light-driven photodegradation of indigo carmine

The removal of toxic organic pollutants from wastewater using reduced graphene oxide (rGO) based photocatalysts has dominated recent scientific research. As a result numerous nanomaterials have been studied and used for wastewater remediation. ZnS has been widely studied due to its versatile application in photocatalysis. This study presents the synthesis of a series of Pd-decorated ZnS/rGO nanocomposites by a coprecipitation method. The materials were characterized using Raman spectroscopy, Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), transmission electron microscopy (TEM), scanning electron microscopy (SEM)–EDS, UV/visible spectrophotometry, and BET surface area analysis. Indigo carmine (IC) dye (20 ppm) was chosen as a model for organic pollutants and was used to evaluate the photocatalytic performance of the Pd–ZnS/rGO nanocomposites under simulated solar light with varying concentrations of Pd in the host material. Pd–ZnS/rGO showed significant visible light induced photocatalytic activity towards the degradation of IC. Highest photocatalytic activity was observed for the 1.0% Pd–ZnS/rGO sample (k=2.19×10−2 min−1).