Adjusting the electromagnetic parameters by decorating magnetic particles for improved impedance matching is an important strategy for obtaining lightweight and efficient carbon-based electromagnetic wave-absorbing materials. In this work, a tomato-like hierarchical porous FeCo/C@WC was prepared for efficient microwave absorption, in which a lightweight anisotropic wood carbon aerogel (WC) was used as a structural assistant, and a MOF-derived graphitized carbon-coated FeCo alloy (FeCo/C) served as a dielectric/magnetic regulator. The tomato-like polystage micro-nano construction was made up of a “pericarp” left by the parallel channels of natural wood, a “pulp tissue” of the MOF-derived nanocage and “seeds” of FeCo nanoalloys embedded in a nanocage. The macroporous wooden shell and mesoporous carbon nanocage gave the composite an excellent hierarchical dielectric coupling network. Meanwhile, the uniformly dispersed FeCo nanoparticles enhanced the magnetic loss to the carbonaceous substrate, allowing for better impedance matching. As a result, the constructed multidimensional FeCo/C@WC exhibited superior wave absorbing ability, in which the maximum reflection loss (RL) reached −47.6 dB and the wide absorption bandwidth was up to 8.9 GHz. These excellent results confirmed that wood-based electromagnetic absorption devices may have a good application prospect.

中文翻译：

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在电磁木炭气凝胶中植入具有可调电磁参数的FeCo / C纳米笼，以有效地吸收微波

通过装饰磁性颗粒以改善阻抗匹配来调节电磁参数是获得轻巧高效的碳基电磁波吸收材料的重要策略。在这项工作中，制备了一种番茄样的分层多孔FeCo / C @ WC以有效地吸收微波，其中使用轻质各向异性的木质碳气凝胶（WC）作为结构助剂，并使用MOF衍生的石墨化碳包覆的FeCo合金（FeCo / C）用作介电/磁调节器。番茄状的多级微纳结构由天然木材平行通道留下的“果皮”，MOF衍生的纳米笼的“纸浆组织”和嵌入纳米笼的FeCo纳米合金的“种子”组成。大孔木壳和中孔碳纳米笼罩使复合材料具有出色的分层介电耦合网络。同时，均匀分散的FeCo纳米颗粒增强了对碳质基底的磁损耗，从而实现了更好的阻抗匹配。结果，所构造的多维FeCo / C @ WC表现出优异的波吸收能力，其中最大反射损耗（RL）达到-47.6dB，并且宽的吸收带宽高达8.9GHz。这些优异的结果证实了木质电磁吸收装置可能具有良好的应用前景。所构建的多维FeCo / C @ WC表现出优异的吸波能力，最大反射损耗（RL）达到-47.6 dB，宽吸收带宽高达8.9 GHz。这些优异的结果证实了木质电磁吸收装置可能具有良好的应用前景。所构建的多维FeCo / C @ WC表现出优异的吸波能力，最大反射损耗（RL）达到-47.6 dB，宽吸收带宽高达8.9 GHz。这些优异的结果证实了木质电磁吸收装置可能具有良好的应用前景。