Multi-interface engineering in MOF-derived magnetic-carbon hierarchical core-shell assembly for broadband electromagnetic wave attenuation integrated with thermal insulation

The expanding applications of electromagnetic (EM) wave absorption materials demand broadband absorption coupled with thermal insulation and lightweight properties. Metal-organic framework (MOF)-derived magneto-electric multi-component structures provide a promising platform for designing efficient absorbers. However, precise control over their configuration, composition, and heterogeneous interfaces remains a critical challenge. Herein, a pomegranate-like Ni/C@C microsphere architecture with abundant heterogeneous interfaces is fabricated by the in-situ polymerization and follow-up pyrolysis treatments. This composite material with its rich multicomponent interfaces, unique three-dimensional conductive network, and magnetic-dielectric synergistic system, exhibits a remarkable effective absorption bandwidth (EAB) of 9.28 GHz at a thickness of 2.0 mm. More excitingly, broadband and high absorption performance was achieved after the numerical simulation of periodic metastructures. The EAB of the composite material can be extended to an astonishing 15.14 GHz, with a minimum reflection loss of -55 dB. Furthermore, the excellent thermal insulation property of the hot-pressed composite material makes it suitable for a wider range of applications. This work advances the synthesis and optimization of multifunctional absorbers, accelerating the development of next-generation microwave absorption materials.