The hollow porous structure with exceptional interfacial effect and customizable internal environment shows significant potential for application as electromagnetic shielding and absorption materials. However, designing hollow porous electromagnetic absorbers with both desirable impedance matching and high loss capability remains a challenge. Herein, 3D hollow porous electromagnetic microspheres were constructed by assembling 0D Co magnetic nanoparticles, 1D carbon nanotubes, and 2D carbon nanosheets. Due to the sufficient sites for Co²⁺ riveting, the high loading of magnetic carbon nanotubes (CoNC) and porous carbon spheres formed high-density interfaces, enhancing the interfacial polarization. Furthermore, high-density CoNC were grown in situ on the hollow porous carbon (HPC) microsphere, forming a highly dispersed 3D magnetic network that inhibited the aggregation of magnetic nanoparticles and enhanced magnetic coupling. Therefore, the as-prepared CoNC/HPC microspheres exhibited excellent microwave absorption (MA) performance, with a minimum reflection loss of -33.2 dB and an effective bandwidth of 5.5 GHz at a thickness of only 1.8 mm. The interfacial polarization mechanism for enhanced MA performance was demonstrated by electron holography and density functional theory calculations. Magnetic holography and micromagnetic simulations also revealed magnetic confinement and coupling mechanism. This work provides a new approach for designing electromagnetic absorbers with optimized impedance matching and loss capability.

具有优异界面效应和可定制内部环境的中空多孔结构显示出作为电磁屏蔽和吸收材料的巨大应用潜力。然而，设计具有理想阻抗匹配和高损耗能力的中空多孔电磁吸收器仍然是一个挑战。在此，通过组装0D Co磁性纳米颗粒、1D碳纳米管和2D碳纳米片构建了3D中空多孔电磁微球。由于有足够的Co ^2+位点铆接过程中，高负载量的磁性碳纳米管（CoNC）和多孔碳球形成高密度界面，增强了界面极化。此外，高密度CoNC在空心多孔碳（HPC）微球上原位生长，形成高度分散的3D磁网络，抑制磁性纳米颗粒的聚集并增强磁耦合。因此，所制备的CoNC/HPC微球表现出优异的微波吸收（MA）性能，在厚度仅为1.8 mm的情况下，最小反射损耗为-33.2 dB，有效带宽为5.5 GHz。通过电子全息术和密度泛函理论计算证明了增强 MA 性能的界面极化机制。磁全息术和微磁模拟还揭示了磁约束和耦合机制。这项工作为设计具有优化阻抗匹配和损耗能力的电磁吸收器提供了一种新方法。