▎ 摘　　要

This paper reports a facile strategy for one-step synthesis of graphene anchored with super-tiny (< 5 nm) nickel nanoparticles (graphene@Ni) with high perfomance microwave absorption. The phase structure, morphology and magnetism of graphene@Ni were characterized by X-ray diffraction (XRD), scanning electron microscope (SEM), transmission electron microscope (TEM) and vibrating sample magnetometer (VSM), respectively. The magnetic Ni nanoparticles with 2.45 nm in average size are densely anchored on the surface of graphene. The electromagnetic characteristics of graphene@Ni compounds were measured by vector network analyzer using a coaxial line method in the frequency range of 1-18 GHz. The reflection loss (RL) of graphene@Ni reaches - 53.92 dB at 9.5 GHz with a thickness of 2.8 mm, and the maximum effective absorption bandwidth with RL values lower than - 10 dB is 5.44 GHz covering from 11.45 to 16.89 GHz at a thickness of 2.1 mm, showing that both of the RLmin and absorption bandwidth for graphene@Ni are obviously enhanced with thinner thickness compared to pure Ni NPs and graphenes. The real RL of graphene@Ni modified aramid fabrics/bismaleimide composite laminate is also measured for comparison, which is basically consistent with simulated results of graphene@Ni. Therefore, the graphene@Ni compounds have advantage in practice for high performance microwave absorption applications.