Cobalt-doped ZnS-reduced graphene oxide nanocomposite as an advanced photocatalytic material

The removal of toxic organic pollutants from wastewater by graphene-based photocatalysts has dominated recent scientific research. As a result numerous nanomaterials have been studied and used for water remediation. ZnS has been widely studied due to its versatile application in photocatalysis. This study presents the synthesis of Co-doped graphene–ZnS nanocomposite by co-precipitation method. The materials were characterized by X-ray diffraction , Raman spectroscopy, Fourier transform infrared spectroscopy, scanning electron microscopy, transmission electron microscopy and Brunauer–Emmett–Teller surface area analysis. UV/Vis diffuse reflectance spectroscopy was employed to estimate band gap energies. Laboratory experiments with indigo carmine (IC) dye was chosen as a model for organic pollutants and was used to evaluate the photocatalytic performance of Co-doped ZnS–rGO nanocomposite under visible light. The Co-doped ZnS–rGO showed significant visible light induced photocatalytic activity towards the degradation of IC. Highest photocatalytic activity was observed for the 0.3 % Co-doped ZnS–rGO sample (k = 3.1 × 10⁻² min⁻¹).