Strategically designed reduced graphene oxide based magnetic responsive nanocatalysts for the attenuation of recalcitrant pollutants

Abstract

The present work attempts to capture the augmentation in the catalytic activity of ferrite (MFe2O4) nanoparticles by employing reduced graphene oxide (RGO) as its solid support that not only provides space for dispersion but also increases the catalytically active sites of nanoferrites. MFe2O4/xRGO (M = Co, Ni and x = 0, 10, 20, 30, 40 wt% GO) were prepared via facile hydrothermal method and their physical characteristics were probed by FT-IR, XRD, FE-SEM, HR-TEM, VSM and BET analysis. Furthermore, the fabricated samples were explored as versatile catalysts for the remediation of hazardous environmental pollutants via oxidation of a cationic dye, an anionic dye and an antibiotic; and reduction of 2-, 3- and 4-nitrophenol. The catalytic behavior of MFe2O4/xRGO was found to be dependent on presence of RGO as solid support as well as on the amount of GO added. The synergistic interaction between dispersed ferrite nanoparticles and RGO sheet was the reason behind the superior catalytic activity of RGO supported nanoferrites in comparison with pure nanoferrites, whereas the increase in specific surface area accounted for augmented activity with increased GO content. High reaction rates were observed even in the absence of light irradiation using MFe2O4/RGO nanocomposites for oxidation reactions. However, for the reduction of nitrophenols, the introduction of RGO resulted in the transformation of inactive CoFe2O4 into highly active catalysts. Also, the usage of just 2 mol% of RGO supported nanoferrites gave astonishing reduction rates. Moreover, the nanocomposites manifested excellent recyclability furthering the humanitarian cause to remove environmental pollutants.