FeNi nanoparticles embedded reduced graphene/nitrogen-doped carbon composites towards the ultra-wideband electromagnetic wave absorption.

A unique reduced graphene oxide (rGO)/nitrogen doped carbon (N-C)/FeNi hybrid was successfully synthesized via a green and environmentally friendly process by means of one pot method. The morphology, phase structure, composition and electromagnetic (EM) wave absorption behavior of all hybrids were studied in detail. All rGO/N-C/FeNi hybrids are composed of rGO sheets on which there are nitrogen doped carbon and FeNi nanoparticles, and the novel structure endows the absorber with multiple scattering and reflection, interfacial polarization, dipole polarization and so on, further bringing remarkable EM wave absorption behavior. Moreover, the complex permittivity of rGO/N-C/FeNi hybrids is able to be controlled through changing the amount of GO. All results show that the rGO/N-C/FeNi-3 hybrid displays a substantial improvement in EM wave absorption performance compared with other hybrids. The minimum reflection loss (RL) value is -68.87 dB at 12.08 GHz with the thickness of 2.5 mm and the largest effective absorption bandwidth (EAB) achieves 6.88 GHz at 2.2 mm with RL value of -14.73 dB at 12.16 GHz. Our research proves that the unique structure and composition have the potential to elevate EM wave absorption performance.