In-situ hydrothermal synthesis of NiCo alloy particles@hydrophilic carbon cloth to construct corncob-like heterostructure for high-performance electromagnetic wave absorbers

NiCo alloy particles (NiCo-APs)@hydrophilic carbon cloth (HCC) composites were successfully prepared by uniformly decorating magnetic NiCo-APs on the surface of three-dimensional HCC by employing an in-situ hydrothermal method. The NiCo-APs@HCC composites exhibited a unique corncob-like network structure that helped improve the electromagnetic wave (EMW) absorption performance of composites. The EMW absorption properties of the composites could be controlled by altering the Ni/Co molar ratio. The optimal minimum reflection loss (RLmin) of -41.80 dB was achieved with the NiCo-APs@HCC composite thickness of 2.29 mm. The effective absorption bandwidth (EAB) reached the maximum of 5.8 GHz, spanning nearly the entire Ku band. In addition, the improved EMW absorption performance was further promoted by favorable impedance matching, strong conduction loss, magnetic loss, dipole polarization, interface polarization, multiple reflections, and scattering. A novel strategy for designing magnetic metal/carbon matrix composites with excellent EMW absorption performance is reported in this study.