Electromagnetic coupling induced by cross-scale synergistic manipulation to boost broadband microwave absorption of Co-MOF derived carbon metamaterial

The resin matrix composite endowed with wide-frequency (4–18 GHz) absorption functionality remains a challenging issue in the current research of microwave absorption materials. Herein, we have developed coral-like Co@NCP reinforced polylactic acid resin (PLA) composites featuring wide-band absorption through cross-scale design, thereby breaking through the current bottleneck of narrow effective absorption band (EAB). Multiple electromagnetic (EM) loss mechanisms, encompassing conductivity loss, dipole polarization, interface polarization and coupling effect were established and optimized by conducting Co-doped defect design at the atomic scale, CoC_x-Co_xP heterogeneous interface design at the nano scale and periodic design at the millimeter scale. The wide absorption in the frequency of 2.0–17.4 GHz of Co@NCP composite is accomplished by the frequency response characteristic of the cooperative multiple absorption mechanism. Accordingly, combined with special cylindrical periodic structure design, the metamaterial absorbers exhibit remarkable EM wave absorption performance (e.g., actual EAB in 15.4 GHz and simulated reflectivity in −65.5 dB). Moreover, large-scale production of the metamaterial absorbers at low costs are realized, which has tremendous application potentiality for developing EM wave absorbers with superior performance.