Magnetic metal nanostructures have exhibited good electromagnetic wave (EMW) absorption properties. However, the surface of the nanostructures is easily oxidized upon exposure to air, leading to the bad stability of the EMW absorption properties. We use metal–organic framework structure as a template to fabricate hollow N-doped carbon polyhedron containing CoNi alloy nanoparticles embedded within N-doped graphene ([email protected]). The atomic ratio of Co/Ni can be tuned from 1:0.54 to 1:0.91 in the hollow [email protected] Experimental results demonstrate that the EMW absorption properties of the [email protected] can be improved through the Ni introduction and increased with an increase of the Ni content. Typically, the minimal reflection loss of the optimal [email protected] can reach −24.03 dB and the effective absorption bandwidth (reflection loss below −10 dB) is as large as 4.32 GHz at the thickness of 2.5 mm. Furthermore, our [email protected] exhibit favorably comparable or superior EMW absorption properties to other magnetic absorbers. In addition, because the CoNi alloy nanoparticles are coated with N-doped graphene layers, their surface oxidation behavior can be efficiently limited. The mechanism of the enhanced EMW absorption property is relevant to the enhanced dielectric loss and better impedance matching characteristic caused by the Ni incorporation.

中文翻译：

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空心N掺杂碳多面体的CoNi合金纳米粒子嵌入高性能N掺杂石墨烯中作为高性能电磁波吸收材料

磁性金属纳米结构具有良好的电磁波（EMW）吸收性能。然而，纳米结构的表面在暴露于空气时容易被氧化，导致EMW吸收特性的差的稳定性。我们使用金属-有机骨架结构作为模板来制造嵌入N掺杂石墨烯中的中空N掺杂碳多面体，其中包含CoNi合金纳米颗粒（[受电子邮件保护]）。空心[电子邮件保护的]中Co / Ni的原子比可以从1：0.54调整到1：0.91。实验结果表明，通过引入镍可以改善[电子邮件保护的]的EMW吸收性能，并随镍含量的增加而增加。镍含量的增加。通常，最佳[受电子邮件保护]的最小反射损失可以达到-24。03 dB时，有效吸收带宽（反射损耗低于-10 dB）在2.5 mm的厚度下高达4.32 GHz。此外，我们的[受电子邮件保护]具有与其他磁性吸收体相当的可比性或优越的EMW吸收特性。另外，由于CoNi合金纳米颗粒涂覆有N掺杂的石墨烯层，因此可以有效地限制其表面氧化行为。增强的EMW吸收特性的机理与由Ni的引入引起的增强的介电损耗和更好的阻抗匹配特性有关。因为CoNi合金纳米颗粒涂有N掺杂的石墨烯层，所以可以有效地限制其表面氧化行为。增强的EMW吸收特性的机理与由Ni的引入引起的增强的介电损耗和更好的阻抗匹配特性有关。因为CoNi合金纳米颗粒涂有N掺杂的石墨烯层，所以可以有效地限制其表面氧化行为。增强的EMW吸收特性的机理与由Ni的引入引起的增强的介电损耗和更好的阻抗匹配特性有关。