Size-controllable synthesis of Fe3O4 nanospheres decorated graphene for electromagnetic wave absorber

A large-area reduced graphene oxide (RGO)/Fe3O4 nanocomposite has been synthesized for electromagnetic wave absorber by a simple hydrothermal method. A series of characterization methods including transmission electron microscopy, X-ray diffraction, Raman spectroscopy and vibrating sample magnetometer indicate that masses of Fe3O4 nanospheres are well decorated on the thin RGO sheets and the nanocomposite exhibit ferromagnetic behavior at room temperature. Moreover, the size of Fe3O4 nanospheres which are decorated on RGO surface can be controlled by adjusting the concentration of FeCl3·6H2O in ethylene glycol/diethylene glycol binary solvent mixtures. Electromagnetic wave absorption properties of the as-synthesized nanocomposite have been investigated by a vector network analyzer between 2 and 18 GHz at room temperature. The electromagnetic data demonstrate that the Fe3O4/RGO nanocomposite can be a powerful candidate in the field of electromagnetic wave absorption, which probably originates from the proper electromagnetic match and strong electromagnetic wave attenuation in the materials. A possible formation mechanism of Fe3O4/RGO nanocomposite based on the hydrothermal method has also been proposed.