Synthesis of core-shell fishbone-like Cu@Ni composites and their electromagnetic wave absorption properties

In this work, core-shell fishbone-like Cu@Ni composites have been successfully prepared via a facile solution reduction method. The morphology, structure and microwave absorption (MA) properties of Cu@Ni paraffin composites were investigated. The results demonstrate that the fishbone-like Cu@Ni composites have core-shell heterostructure with Cu as the core and Ni as the shell. And the Cu@Ni paraffin-composite containing 50 wt% Cu@Ni exhibits excellent electromagnetic wave absorption properties. The minimum reflection loss (RLmin) of -32.2 dB can be observed at 8.2 GHz and the bandwidth with RL less than -10 dB reaches 13.2 GHz (4.8-18.0 GHz) with a thin absorber thickness between 1.0 and 3.0 mm. The prominent microwave absorption properties mainly come from its synergistic advantage of magnetic loss and dielectric loss. Besides, this novel fishbone-like Cu@Ni structure is also beneficial to enhance electromagnetic-wave-absorbing properties due to the multiple reflections and scattering that occurs in the branch of fishbone-like structure. Furthermore, the one-dimensional fishbone is supposed to be as antenna tip, which can receive more waves and consume more electromagnetic energy. (C) 2017 Published by Elsevier B.V.