In order to widen the application field of microwave absorption (MA) materials, it is still challenging to obtain high-performance MA materials with wide frequency bandwidth, lightweight, thin thickness, and strong absorption by an economical and sustainable method. Herein, the novel coral-like hierarchical structure with zero-dimensional Fe nanocrystals, one-dimensional N-doped carbon nanotubes (CNTs) and three-dimensional porous carbon (PC) matrix is rationally constructed to enhance MA performance. Based on renewable biomass residues, the composite consisted of PC as matrix, bamboo-shaped CNTs with magnetic nanoparticles at the top grow on the surface of PC. By controlling the growth conditions of carbon nanotube, the microstructure and dielectric loss capacity of composite can be manipulated to optimize the impedance matching, reflection loss (RL), and effective absorption bandwidth (EAB, the bandwidth of RL < -10 dB). Benefitting from the unique architecture and hierarchical composite, the composite exhibited a minimum RL of −70 dB at thin thickness of 1.9 mm under low filler content of 12.5 wt%. Even with the thickness of 1.5 mm, the RL could reach −51.8 dB with a broadcast EBA of 5.0 GHz. This work provides an insight for designing advanced microwave absorbers with lightweight, thin thickness, strong RL, and wide EAB.

为了拓宽微波吸收（MA）材料的应用领域，通过经济且可持续的方法获得具有宽频带宽、重量轻、厚度薄、吸收强的高性能MA材料仍然具有挑战性。在此，合理构建了具有零维 Fe 纳米晶体、一维 N 掺杂碳纳米管 (CNT) 和三维多孔碳 (PC) 基质的新型珊瑚状分层结构，以提高 MA 性能。该复合材料基于可再生的生物质残留物，以 PC 为基体，顶部带有磁性纳米粒子的竹状碳纳米管生长在 PC 表面。通过控制碳纳米管的生长条件，可以操纵复合材料的微观结构和介电损耗能力来优化阻抗匹配，反射损耗 (RL) 和有效吸收带宽 (EAB，RL < -10 dB 的带宽)。得益于独特的结构和分层复合材料，该复合材料在 12.5 wt% 的低填料含量下，在 1.9 mm 的薄厚度下表现出 -70 dB 的最小 RL。即使厚度为 1.5 毫米，RL 也可以达到 -51.8 dB，广播 EBA 为 5.0 GHz。这项工作为设计具有重量轻、厚度薄、强 RL 和宽 EAB 的先进微波吸收器提供了见解。0 吉赫兹。这项工作为设计具有重量轻、厚度薄、强 RL 和宽 EAB 的先进微波吸收器提供了见解。0 吉赫兹。这项工作为设计具有重量轻、厚度薄、强 RL 和宽 EAB 的先进微波吸收器提供了见解。