Facile preparation of octahedral Fe3O4/RGO composites and its microwave electromagnetic properties

The novel octahedral Fe3O4/RGO composites with sandwich-like structures were synthesized through ultrasonic and thermal reduction process. The octahedral Fe3O4 nanoparticles were incorporated into the RGO by coordination bonding, which was confirmed by Fourier-transform infrared spectroscopy and scanning electron microscopy. Compared with octahedral Fe3O4, the obtained composites exhibited an obviously enhanced microwave absorption property which were attributed to the complementarities between the dielectric loss and the magnetic loss. For the octahedral Fe3O4/RGO composites, a wide absorption band less than -10 dB was in the range of 3-18 GHz. Moreover, the bandwidth of R-L exceeded -20 dB (99 % absorption) over 5 GHz (12-16 and 17-18 GHz). In addition, the maximum R-L was up to -65 dB at a thickness of 1.8 mm. All the results suggested that it provided a facile method to fabricate novel electromagnetic wave-absorption materials.