Owing to the tunable compositions and versatile functionality, the development of eco-friendly metal-phenolic coordination crystals derivatives is highly anticipated for electromagnetic wave absorption. In this study, three kinds of magnetic hollow carbon spheres (HCSs) with macro-meso-microporous characteristics, including Fe/HCS, Co/HCS, and CoNi/HCS, are successfully fabricated via the co-operative hard template and self-assembling process, in which magnetic particles are encapsulated in carbon shell matrix after the pyrolysis of metal–polyphenol coordination crystals and further subsequent template removal. On the one hand, hierarchical macro-meso-micropores effectively balance the impedance gap between absorbers and air and introduce structural defects or distortion, leading to matched impedance and enhanced dipolar/defect polarization. On the other hand, wrapped magnetic particles provide uncountable hetero-interfaces and induce ferromagnetic resonance, resulting in strengthened interfacial polarization and additional magnetic loss. In particular, enhanced minimum reflection loss (R_L,min) and broadband effective absorption bandwidth (EAB) are achieved with only 10 wt.% filler loading. Specifically, the R_L,min and EAB values are −57.5 dB and 7.2 GHz for Fe/HCS, −50.0 dB and 5.8 GHz for Co/HCS, and −52.1 dB and 6.7 GHz for CoNi/HCS, respectively. Moreover, this work provides us a modular-assembly strategy to regulate the hollow cavity of absorbers and simultaneously manipulates the chemical components of absorbers to regulate electromagnetic wave absorption performance.

由于成分可调和功能多样，环保型金属酚配位晶体衍生物的开发在电磁波吸收方面备受期待。本研究通过协同硬模板和自组装成功制备了三种具有宏观-介观-微孔特性的磁性空心碳球（HCS），包括Fe/HCS、Co/HCS和CoNi/HCS。该过程中，金属-多酚配位晶体热解并进一步去除模板后，磁性颗粒被封装在碳壳基质中。一方面，分层的宏观-介观-微孔有效地平衡了吸收体和空气之间的阻抗间隙，并引入结构缺陷或变形，从而导致匹配的阻抗和增强的偶极/缺陷极化。另一方面，包裹的磁性颗粒提供了无数的异质界面并诱发铁磁共振，导致界面极化增强和额外的磁损耗。特别是，增强的最小反射损耗（仅用 10 wt.% 的填料负载即可实现R _{L,min ）和宽带有效吸收带宽 (EAB)。}具体而言， Fe/HCS 的R _L,min和 EAB 值分别为 -57.5 dB 和 7.2 GHz，Co/HCS 的 R L,min 和 EAB 值分别为 -50.0 dB 和 5.8 GHz，CoNi/HCS 的 R L,min 和 EAB 值分别为 -52.1 dB 和 6.7 GHz。此外，这项工作为我们提供了一种模块化组装策略来调节吸波体的空腔，同时操纵吸波体的化学成分来调节电磁波吸收性能。