Controllable synthesis, magnetism and solubility enhancement of graphene nanosheets/magnetite hybrid material by covalent bonding

Hybrids of Fe3O4 nanoparticles and surface-modified graphene nanosheets (GNs) were synthesized by a two-step process. First, graphene nanosheets were modified by SOCl2 and 4-aminophenoxyphthalonitrile to introduce nitrile groups on their surface. Second, the nitrile groups of surface-modified graphene nanosheets were reacted with ferric ions on the surface of Fe3O4 with the help of relatively high boiling point solvent ethylene glycol to form a GNs/Fe3O4 hybrid. The covalent attachment of Fe3O4 nanoparticles on the graphene nanosheet surface was confirmed by Fourier-transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), energy-dispersive X-ray spectrometer (EDS) and scanning electron microscopy (SEM). TEM and HRTEM observations indicated that the sizes of the nanoparticles and their coverage density on GNs could be easily controlled by changing the concentration of the precursor and the weight ratio to GNs. Magnetic measurements showed that magnetization of the hybrid materials is strongly influenced by the reaction conditions. Chemically bonded by phthalocyanine, the solubility of as-synthesized GNs/Fe3O4 hybrid materials was greatly enhanced, which was believed to have potential for applications in the fields of composites, wastewater treatment and biomaterials.

Novel graphene nanosheets (GNs)/Fe3O4 hybrid materials with enhanced solubility were synthesized via covalent bonding in a simple solvothermal system; the size and coverage density of Fe3O4 nanoparticles deposited on GNs can be controlled by changing the synthesized parameters.Figure optionsDownload high-quality image (108 K)Download as PowerPoint slideHighlights
► Novel graphene nanosheets/Fe3O4 hybrids were synthesized by covalent bonding.
► Stable interaction between nitriles and iron ion promoted deposition of Fe3O4.
► The size and density of Fe3O4 nanoparticles deposited on GNs can be controlled.
► Solubility of hybrids was greatly enhanced by phthalocyanine covalent bonding.