Preparation of magnetic CoFe2O4-functionalized graphene sheets via a facile hydrothermal method and their adsorption properties

Magnetic CoFe2O4-functionalized graphene sheets (CoFe2O4-FGS) nanocomposites have been synthesized by hydrothermal treatment of inorganic salts and thermal exfoliated graphene sheets. Scanning electron microscopy (SEM) and transmission electron microscopy (TEM) observations show that cobalt ferrite nanoparticles with sizes of 10-40 nm are well dispersed on graphene sheets. OH- was recognized as a tie to integrate the inorganic salts with the graphene sheets, which made reaction started and developed on the surface of graphene sheets and formed cobalt ferrite nanoparticles on graphene sheets. The adsorption kinetics investigation revealed that the adsorption of methyl orange from aqueous solution over the as-prepared CoFe2O4-FGS nanocomposites followed pseudo-second-order kinetic model and the adsorption capacity was examined as high as 71.54 mg g(-1). The combination of the superior adsorption of FGS and the magnetic properties of CoFe2O4 nanoparticles can be used as a powerful separation tool to deal with water pollution. (C) 2011 Published by Elsevier Inc.