Abstract The preparation of magnetic metal/carbon composites by pyrolysis of metal organic framework (MOFs) have great potential in lightweight electromagnetic (EM) wave absorption. Nevertheless, it is of great significance to design the three-dimensional (3D) hierarchical structure with synergistic effect from unique MOFs for enhancing the EM wave absorption performance. More importantly, through pyrolysis of MOF, the uniform distribution of magnetic metal and carbon material can be controlled. Herein, Co/Zn-MOF-11 microspheres are used as a precursor pyrolyzed in argon atmosphere to prepare 3D hierarchical rambutan-like bimetallic/carbon@carbon nanotubes (RBC@CNTs) composites. The RBC@CNTs composite pyrolyzed at 800 °C exhibits excellent EM wave absorption performance due to the unique structure and multiple loss mechanisms. A maximum reflection loss of −49.8 dB at 13.6 GHz can be achieved when the filler loading of 3D hierarchical RBC@CNTs composite is 20 wt% with the thickness of 2.4 mm. In addition, the effective absorption bandwidth achieves 5.5 GHz (RL ≤ −10 dB). This strategy to synthesis a unique hierarchical structure is instrumental in enhancing the attenuation of EM wave.

中文翻译：

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类红毛丹的碳纳米管改性CoZn/C复合材料应用于电磁波吸收

摘要 通过金属有机骨架（MOFs）热解制备磁性金属/碳复合材料在轻质电磁（EM）波吸收方面具有巨大潜力。尽管如此，设计具有独特MOFs协同效应的三维（3D）层次结构对于增强EM波吸收性能具有重要意义。更重要的是，通过MOF的热解，可以控制磁性金属和碳材料的均匀分布。在此，Co/Zn-MOF-11 微球用作在氩气气氛中热解的前驱体，以制备 3D 分级红毛丹状双金属/碳@碳纳米管（RBC@CNTs）复合材料。由于独特的结构和多重损耗机制，在 800°C 下热解的 RBC@CNTs 复合材料表现出优异的电磁波吸收性能。当 3D 分层 RBC@CNTs 复合材料的填料负载为 20 wt% 且厚度为 2.4 mm 时，在 13.6 GHz 下的最大反射损耗为 -49.8 dB。此外，有效吸收带宽达到 5.5 GHz (RL ≤ -10 dB)。这种合成独特层次结构的策略有助于增强电磁波的衰减。