Hu Haihua, Zheng Yun, Ren Kun, Wang Jieying, Zhang Yanhui, Zhang Xuefeng, Che Renchao, Qin Gaowu, Jiang Yong
Key Laboratory for Anisotropy and Texture of Materials (MOE), School of Materials Science and Engineering, Northeastern University, Shenyang 110819, People's Republic of China.
Institute of Advanced Magnetic Materials, College of Materials and Environmental Engineering, Hangzhou Dianzi University, Hangzhou 310012, People's Republic of China.
Nanoscale. 2021 Feb 4;13(4):2324-2332. doi: 10.1039/d0nr08245g.
Constructing carbon nanotube (CNT) based heterostructures has proven to be an effective way of improving the microwave absorption (MA) capability of these materials, regardless of whether the heterostructures are located on the inner or outer walls of the CNTs. However, the potential of the two sides of CNTs for constructing efficient MA heterostructures has not been compared, and the underlying mechanism behind this difference has not been determined. Therefore, CNT based heterostructures with Fe2O3 nanoparticles inside (Fe2O3-in-CNTs) and outside (Fe2O3-out-CNTs) of the CNTs were synthesized and characterized. The minimum reflection loss and maximum effective bandwidth of the Fe2O3-in-CNTs are -34.1 dB at 3.0 mm and 5.1 GHz at 2.6 mm, much better than those of the Fe2O3-out-CNTs. Stronger interfacial polarization at the inner surface of the CNTs than at the outer surface was confirmed using off-axis electron holography, which is regarded as the key factor that determines the excellent MA performance of the heterointerface constructed by the inner surface of the CNTs. The attractive potential of the inner surface of CNTs for constructing highly efficient MA heterostructures has, to our knowledge, not been proposed before, the findings of which can shed the light on the approach of developing CNT composited MA materials that have outstanding MA properties.
事实证明，构建基于碳纳米管（CNT）的异质结构是提高这些材料微波吸收（MA）能力的有效方法，无论这些异质结构位于碳纳米管的内壁还是外壁。然而，尚未比较碳纳米管两侧构建高效MA异质结构的潜力，也尚未确定这种差异背后的潜在机制。因此，合成并表征了碳纳米管内部（Fe2O3-in-CNTs）和外部（Fe2O3-out-CNTs）含有Fe2O3纳米颗粒的基于碳纳米管的异质结构。Fe2O3-in-CNTs的最小反射损耗和最大有效带宽在3.0 mm处为-34.1 dB，在2.6 mm处为5.1 GHz，远优于Fe2O3-out-CNTs。使用离轴电子全息术证实，碳纳米管内表面的界面极化比外表面更强，这被认为是决定由碳纳米管内表面构建的异质界面优异MA性能的关键因素。据我们所知，此前尚未提出碳纳米管内表面在构建高效MA异质结构方面的诱人潜力，其研究结果可为开发具有出色MA性能的碳纳米管复合MA材料的方法提供启示。
