Fabrication of Co Nanoparticles Supported on Magnetic Graphene Oxide and Their Application as a Recoverable Catalyst and their Antioxidant Capacity Assessment

In the present study, the magnetically separable Co/Fe3O4/rGO nanocomposite was synthesized through a green route at the room temperature using salvia mirzayanii peel extract as a reducing and stabilizing agent. These nanoparticles were compared by techniques, such as FTIR, SEM, EDX, and UV-Visible which carried out to analyze their crystallite sizes, functional groups, morphologies, optical, and magnetic properties. Initially, cobalt, iron, and hybrid of iron-cobalt nanoparticles were synthesized by plant extracts. UV-Visible spectroscopy of these nanoparticles showed an maximam absorption at 370, 442, and 430 nm, respectively, which confirmed the ability of the plant extract for the synthesis of these nanoparticles. The obtained nanoparticles displayed potential efficiency for the degradation of dye pollutants as catalysts with using of NaBH4 as a reducing agent. The result showed that Co/Fe3O4/rGO nanocomposites have higher ability for the reduction of phenol red and boromothymol blue higher than Co and Co-Fe which presents 97 and 97.5 % decrease the maximum absorbtion of these dyes, respectively. Furthermore, the antioxidant potential of these nanoparticles using various in vitro systems such as metal chelating, phosphomolybdenum, and ferric reducing antioxidant power (FRAP) activities and 2,2-azinobis-(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) were performed. Radical scavenging activity of ABTS showed the (IC50) values 50 and 75 mg/ml for Co/Fe3O4/rGO and plant extract, respectively, as compared with ascorbic acid as a refrence. These results presented the high potentioal of these nanoparticles on the antioxidant capacity assay of the medicinal plants.