Synthesis and microwave absorption properties of reduced graphene oxide-magnetic porous nanospheres-polyaniline composites

A ternary composite which was composed of reduced graphene oxide (R-GO), Fe3O4 porous nanospheres (P-Fe3O4) and polyaniline (PANI) was synthesized by a facile route. The microstructure of the composite was characterized by XRD, FT-IR, FESEM and TEM. The results indicated that the uniform Fe3O4 porous nanospheres with the average size of 250-400 nm were grown on R-GO sheets and the coating layer of PANI covered over the surface of R-GO/P-Fe3O4 composite. With the decreasing content of Fe3O4, the saturation magnetization of this ternary composite declined while the coercivity showed the opposite trend. The composite showed excellent microwave absorption properties due to the good impedance match characteristic between dielectric loss and magnetic loss. The minimum reflection loss value reached −29.51 dB at 14.69 GHz with thickness of 1.0 mm.