Lv Shu-Qing, Han Peng-Zhao, Zhang Xiao-Juan, Wang Guang-Sheng
School of Civil Engineering and Architecture, Northeast Electric Power University Jilin 132012 PR China.
School of Chemistry, Beihang University Beijing 1000191 PR China
RSC Adv. 2021 Sep 23;11(50):31499-31504. doi: 10.1039/d1ra06050c. eCollection 2021 Sep 21.
Magnetic metal nanocrystals tend to be advanced microwave absorption substances as they possess simultaneous dielectric and magnetic losses. In this study, the metallic cobalt (Co) nanocrystals with a pine needle-like nanostructure constructed by one-dimensional Co nanorods have been successfully prepared through the polyol approach. By regulating the amount of reduced graphene oxide (rGO), rGO/Co nanocomposites with different mass ratios were acquired. Experimental results demonstrate that the rGO/Co nanocomposites display excellent microwave attenuation capacity. The minimum reflection loss value can reach -57.8 dB at 12.43 GHz with a filler loading of 20 wt% at 1.8 mm. Moreover, the effective absorption bandwidth covers the frequency range of 4.2-15.5 GHz with an integrated thickness of 1.5-4.0 mm. The main absorption mechanisms include dielectric loss caused by dipole and interfacial polarization and magnetic loss arising from ferromagnetic resonance and eddy current loss. In addition, the special nanostructure effect is also beneficial to improve the EM wave absorption performance.
磁性金属纳米晶体因其同时具有介电损耗和磁损耗，往往是先进的微波吸收物质。在本研究中，通过多元醇法成功制备了由一维钴纳米棒构建的松针状纳米结构的金属钴（Co）纳米晶体。通过调节还原氧化石墨烯（rGO）的用量，获得了不同质量比的rGO/Co纳米复合材料。实验结果表明，rGO/Co纳米复合材料表现出优异的微波衰减能力。在1.8 mm厚度、填料含量为20 wt%时，最小反射损耗值在12.43 GHz可达-57.8 dB。此外，有效吸收带宽覆盖4.2-15.5 GHz频率范围，集成厚度为1.5-4.0 mm。主要吸收机制包括偶极子和界面极化引起的介电损耗以及铁磁共振和涡流损耗引起的磁损耗。此外，特殊的纳米结构效应也有利于提高电磁波吸收性能。
