Abstract A composite of nitrogen-doped reduced graphene oxide and carbon nanotubes (N-rGO@CNTs) was prepared. As the mass ratio of CNTs to rGO increasing, the conductive pathways inside the N-rGO@CNTs were gradually formed with strong electronic transmission ability, which contributed to the conversion of electromagnetic energy into thermal energy. Besides, the nest-like “CNTs clusters”, abundant wrinkled layers and through-tubes were favorable for multiple scattering and polarization of electromagnetic waves. More electromagnetic waves were further dissipated in the form of thermal energy. Doping of N atoms introduced a large number of defects and electronic dipoles among the carbon lattice, which could induce the polarization relaxation for higher dielectric loss to attenuate more electromagnetic waves. The experimental results suggested that the multi-scale structure endowed the composite with well-matched impedance, rich loss modes and strong loss, attributed to electronic conduction, defects polarization as well as dipolar polarization, etc. The resulted N-rGO@CNTs0.3 exhibited the remarkable microwave absorption performance under the ultra-low mass loading of only 2 wt%. Its effective bandwidth was broad and up to 7.1 GHz (10.5–17.6 GHz) with the minimum reflection loss of −49.4 dB.

中文翻译：

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具有超低微波吸收载荷的多尺度结构氮掺杂rGO@CNTs复合材料

摘要 制备了氮掺杂还原氧化石墨烯和碳纳米管的复合材料（N-rGO@CNTs）。随着碳纳米管与rGO质量比的增加，N-rGO@CNTs内部逐渐形成导电通路，具有较强的电子传输能力，有助于将电磁能转化为热能。此外，巢状的“CNTs簇”、丰富的褶皱层和贯穿管有利于电磁波的多重散射和极化。更多的电磁波以热能的形式进一步消散。N 原子的掺杂在碳晶格中引入了大量缺陷和电子偶极子，这可能会引起极化弛豫，从而导致更高的介电损耗，从而衰减更多的电磁波。实验结果表明，多尺度结构赋予复合材料良好的阻抗匹配、丰富的损耗模式和强损耗，归因于电子传导、缺陷极化以及偶极极化等。得到的 N-rGO@CNTs0.3在仅 2 wt% 的超低质量负载下表现出显着的微波吸收性能。其有效带宽很宽，最高可达 7.1 GHz (10.5–17.6 GHz)，最小反射损耗为 −49.4 dB。