Synthesis and remarkable microwave absorption properties of amine-functionalized magnetite/graphene oxide nanocomposites

Abstract We prepared magnetite nanoparticles by co-precipitation method and functionalized them by amine groups prior to hybridization with graphene oxide. The resulting nanocomposites Fe3O4-NH2/GO were prepared with three weight ratios: 1:1, 2:1, 3:1, [Fe3O4-NH2:GO], in order to compare their magnetic properties. We used different techniques to investigate the nanocomposites: Fourier-transform infrared spectroscopy, X-ray diffraction, scanning electron microscopy and vibrating sample magnetometer (VSM). Our results show that the synthesized nanocomposites exhibit superparamagnetic behavior with magnetic saturation at room temperature of the order of ∼51.52, ∼55.85 and ∼58.26 emu/g respectively, which is large in comparison with Fe3O4 nanoparticles with ∼73.4 emu/g. Microwave absorption of nanocomposite absorber of 7.0 mm thickness showed a minimum reflection loss of −27.85 dB at 4.80 GHz. The band widths corresponding to reflection loss less than −10 dB (over 90% electromagnetic wave absorption) are 3.82 and 2.99 GHz (from 2.58 to 6.40 GHz and from 13.99 to 16.98 GHz). Therefore, our results demonstrate that the prepared Fe3O4-NH2/GO nanocomposites are promising for microwave absorption applications.