High-performance electromagnetic wave absorption of NiCoFe/N-doped carbon composites with a Prussian blue analog (PBA) core at 2-18 GHz

Abstract

Structure design and assembly control are the two key factors in designing new microwave absorbing materials and improving their electromagnetic wave absorption (EMWA) performance; however, balancing the coordination between these factors remains a great challenge. In this manuscript, a coprecipitation method and an in-situ polymerization method were used to construct nitrogen-carbon-doped popcorn-like porous nanocomposites (NiCoFe/NC). The metallic particles were encapsulated in approximately 10 layers of graphite carbon shells, and a NiCoFe/NC core–shell structure was formed. The EMWA properties of the NiCoFe/NC composites were adjusted by varying the divinylbenzene (DVB) to acrylonitrile (AN) content. The optimized NiCoFe/NC composite showed a minimum reflection loss of −57.5 dB and a maximum effective absorption bandwidth (EAB) of 5.44 GHz. The excellent EMWA properties of the NiCoFe/NC composites can be attributed to the synergistic effect among the core–shell structure, popcorn-like structure, magnetic metal, carbon and nitrogen. This effect leads to enhanced impedance matching, interface polarization, dipole polarization, multiple reflection and scattering in the composites. In this paper, an effective strategy for the preparation of high-performance magnetic/dielectric composites is provided by carefully designing a new microstructure.