Synergistic Macro–Micro Structural Design of GO/NiCo2O4/PPy Multiscale Composites for High-Performance Electromagnetic Wave Absorption

With the rapid advancement of electromagnetic technologies, the development of high-performance electromagnetic wave (EMW) absorbing materials is crucial for mitigating radiation, reducing interference, and ensuring information security. In this work, a bioinspired multiscale strategy coupling macroscopic structural design with hierarchical interface engineering was proposed. A gyroid minimal surface was fabricated via high-precision Digital Light Processing (DLP) three-dimensional printing using graphene oxide incorporated photocurable resin to establish a conductive network and customized EMW propagation pathways. Subsequent in-situ growth of NiCo 2 O 4 and polypyrrole (PPy) introduced abundant heterogeneous interfaces and porous microstructures, which synergistically enhanced dielectric loss, magnetic loss, and interfacial polarization while optimizing impedance matching. Benefiting from these multi-level mechanisms, the composite exhibited outstanding broadband absorption performance at relatively small thicknesses. Experimental results demonstrated that the prepared PNGMM2 composite achieved a minimum reflection loss of -57.32 dB at 12.7 GHz with a thickness of 2.67 mm; an effective absorption bandwidth of 6.4 GHz was obtained at 2.42 mm, fully covering the Ku band; and complete coverage of the X band was realized at a thickness of 3.39 mm. This study demonstrates the effective integration of biomimetic architecture, interfacial engineering, and compositional design, offering a feasible pathway toward next-generation lightweight, broadband, and structurally robust EMW absorbers.