Few layer graphene decorated with homogeneous magnetic Fe3O4 nanoparticles with tunable covering densities

Abstract

Magnetic iron oxide nanoparticles (NPs) with narrow size distribution (8 ± 2 nm), well defined chemical composition and crystalline structure are synthesized and homogeneously dispersed onto the surface of few-layer graphene (FLG) via a solvothermal decomposition method. The iron oxide NPs are strongly anchored to the graphene surface and confer a magnetic character to the final composite. The metal oxide/support interaction is high enough to avoid the NPs coalescence and/or agglomeration and thus to preserve the NPs size and dispersion after thermal treatment up to 400 °C. The introduced iron oxide NPs on FLG also play a role of nano-spacers to prevent the re-stacking of the graphene sheets upon the drying process. It is expected that such a composite could find use in several application fields such as catalyst support for liquid-phase reactions with easy magnetic separation, in electrochemical energy storage and in waste water treatment. The ability of the synthesized iron oxide NP/FLG composite to adsorb foreign elements (organic pollutants) is demonstrated in the methylene blue (MB) adsorption and its catalytic properties are evaluated in the selective oxidation of H₂S.