CuFe-MOF-Derived Heterostructures on G/BPNS/CNTs Frameworks for Microwave Absorption and Polystyrene Bead Foam Welding

Abstract A key challenge in lightweight broadband electromagnetic wave (EMW) absorption is balancing strong attenuation, good impedance matching, and structural integrity─excessive conductivity enhances dielectric loss but often causes severe surface reflection that blocks wave penetration. Herein, a 3D xCuFe/GPC heterostructure was constructed by anchoring bimetallic CuFe-MOF derivatives onto a G/BPNS/CNT hybrid conductive framework, where G, P, and C represent graphite, black phosphorus nanosheets, and carbon nanotubes, respectively. CuFe-MOF derivatives provide magnetic-dielectric loss, BPNS introduce phosphorus-related polarization sites, and graphite/CNT meshes build long-range conductive pathways, with CNTs acting as one-dimensional bridges. This coordinated design enables the optimized 0.1CuFe/GPC composite to achieve an RLmin of −46.3 dB at 2.1 mm and an EAB of 4.03 GHz at 1.3 mm. RCS simulations based on a PEC plate model show an RCS reduction exceeding 30 dB. Beyond EMW absorption, 0.1CuFe/GPC serves as a microwave-to-thermal transducer for rapid expandable polystyrene (ePS) foaming, producing lightweight multifunctional foams with robust mechanical integrity. This work provides a practical route toward integrated electromagnetic protection and lightweight structural-functional materials.