BiM@NC (M = Fe, Co, Ni; NC = N‐Doped Carbon) Nanoplates Confined in Wood‐Derived Carbon with Excellent Electromagnetic Wave Absorption Performance

Abstract Wood‐derived carbon offers lightweight properties and periodic channel structures, making it a promising candidate for the application in electromagnetic wave (EMW) regulation. However, its high dielectric behavior limits the impedance matching and ultrathin EMW absorption. Herein, BiM@NC (M = Fe, Co, Ni; NC = N‐doped carbon) nanoplates are embedded into pine wood‐derived carbon (WCA) to fabricate multifunctional EMW absorbers combining thermal stability and acid‐corrosion‐resistance. The constructed dielectric‐magnetic (WCA/BiM@NC) system inherits the 3D periodic rectangular pore channels in the WCA along with the tightly anchored porous BiM@NC nanoplates, which deliver remarkable EMW response behavior. The ratio of the reflection loss ( R L ) to the matching thickness ( d ) reaches 44 dB mm −1 , significantly exceeding those of state‐of‐the‐art EMW absorbers. WCA/BiCo@NC achieves R L values of −50.92 and −31.82 dB at matching thicknesses of 1.40 and 1.29 mm, respectively. Radar cross‐section (RCS) simulations highlight the potential of the dielectric‐magnetic synergist of WCA/BiM@NC for radar evasion. Importantly, WCA/BiM@NC exhibits lightweight construction along with excellent mechanical properties, thermal stability, and acid corrosion resistance. The periodic 3D porous structure of pine wood, the carbon main body, and the NC layer in the composite contribute to the thermal properties and acid resistance.