Study on microwave absorption performance of nickel cobalt bimetallic nanosheet arrays @ hydrophilic carbon cloth composite with core-sheath structure

Abstract

Magnetic metal/carbon matrix composites have gained significant attention as vital microwave absorption materials (MAMs) in recent years, owing to their multifarious microwave loss mechanisms, adjustable chemical composition, and microstructure. In this study, we describe the successful synthesis of nickel-cobalt bimetallic nanosheet arrays @ hydrophilic carbon cloth (NiCo-BNSAs @ HCC) composites with a distinctive core-sheath structure, low density, and high toughness using a solvothermal method followed by a high-temperature pyrolysis process. Despite their low density and high toughness, these composites exhibit outstanding MA properties at low matching thicknesses. Among them, S2 exhibited the minimum reflection loss (RLmin) of −75.4 dB at 1.35 mm, with its optimal effective absorption bandwidth (EAB, RL＜−10 dB) extending to 3.6 GHz at 1.10 mm. Our analysis indicates that the incorporation of NiCo-BNSAs nanosheets not only enhances the multiple scattering of EM waves but also improves interfacial polarization loss and dipole polarization loss. This study provides valuable insights into the rational construction of high-performance magnetic metal/ carbon matrix MAMs with a core-sheath structure.