Magnetic core-shell structural mesoporous carbon materials have an extensive application prospect in microwave absorption because of their comprehensive merits of magnetic function and distinctive mesoporous structure. Herein, magnetic core-shell structural carbon nanotubes@mesoporous N-doped carbon (CoNi/CNTs@mesoNC) nanofibers are successfully fabricated by combining homogeneous coating of mesoporous polydopamine, surface deposition of CoNi-bimetal metal-organic frameworks (MOFs), and in-situ growth of CNTs and CoNi nanoparticles. The resultant CoNi/CNTs@mesoNC nanofibers possess a well-defined hierarchical structure consisting of CNTs core and mesoporous carbon shell distributed with short CNTs and CoNi nanoparticles, high surface area (∼316 m² g⁻¹), high nitrogen content (∼5.5 wt%), and large pore size (∼10 nm). As expected, the rational design of multifunctional components and hierarchical structure endows CoNi/CNTs@mesoNC composites with excellent microwave absorption performance. Particularly, the minimum reflection loss can reach −52.1 dB at 13.4 GHz with only 1.7 mm thickness and the corresponding effective absorption bandwidth is up to 5.2 GHz (12.8–18.0 GHz), outperforming most reported microwave absorbing materials. The microwave absorption mechanism of this material has been deeply investigated and systematically clarified. This work provides meaningful reference for the design and fabrication of functional core-shell microwave absorbers with distinctive mesoporous structure.

磁性核壳结构介孔碳材料因其磁性功能和独特的介孔结构的综合优点，在微波吸收方面具有广泛的应用前景。在此，通过结合介孔聚多巴胺的均匀涂层、CoNi-双金属金属有机框架（MOF）的表面沉积以及- CNT 和 CoNi 纳米粒子的原位生长。所得的CoNi/CNTs@mesoNC纳米纤维具有明确的分级结构，由CNT核和分布有短CNT和CoNi纳米颗粒的介孔碳壳组成，具有高表面积（∼316 m ²  g ^-1）、高氮含量（∼5.5 wt%）和大孔径（∼10 nm）。正如预期的那样，多功能组件和分层结构的合理设计赋予了CoNi/CNTs@mesoNC复合材料优异的微波吸收性能。特别是，在13.4 GHz时，最小反射损耗可达-52.1 dB，厚度仅为1.7 mm，相应的有效吸收带宽高达5.2 GHz（12.8-18.0 GHz），优于大多数报道的微波吸收材料。该材料的微波吸收机理已得到深入研究和系统阐明。该工作为具有独特介孔结构的功能性核壳微波吸收体的设计和制备提供了有意义的参考。