▎ 摘　　要

Microwave-absorbing materials are crucial for the attenuation of microwave radiation, and graphene-based composites have promising applications in this field. In this study, a typical precipitation reduction procedure was used to create the cuboidal-accumulating nickel particles on reduced graphene composites (N1Cn) with an extraordinarily broad absorption. The deposition equilibrium system of the nickel ion in the solution was carefully evaluated, illuminating the essential technological range of nickel ion complete precipitation. The effects of calcination temperature on the phase, morphology, and absorption properties of N1Cn were investigated. The results show that the nickel particles in the form of cubiform accumulation can push apart the lamellar graphene, increasing the interfacial loss and magnetic loss, and thus improve the impedance matching of the whole material. The resulting N1Cn shows a maximum reflection loss of - 67.1 dB at 2.0 mm and 17.6 GHz, which corresponds to an effective bandwidth of 8.7 GHz at a thickness of 2.8 mm. The comprehensive balance of impedance matching and attenuation constants based on various scattering mechanisms, such as polarization relaxation loss, interfacial polarization, eddy current loss, and Ferro-resonance in the N1Cn, might be credited with the superior microwave absorption capabilities.