Cui Guangzhen, Lu Yanli, Zhou Wei, Lv Xuliang, Hu Jiangnan, Zhang Guoyu, Gu Guangxin
Key Laboratory of Science and Technology on Electromagnetic Environmental Effects and Electro-optical Engineering, The Army Engineering University of PLA, Nanjing 210007, China.
The First Scientific Research Institute of WuXi, Wuxi 214035, China.
Nanomaterials (Basel). 2019 Jan 22;9(2):141. doi: 10.3390/nano9020141.
Magnetic nanoparticles, such as Fe₃O₄ and Co₃O₄, play a vital role in the research on advanced microwave absorbing materials, even if problems such as high density and narrow band impedance matching are still unsolved. Herein, the study of lightweight hollow Fe₃O₄@reduced graphite oxide (RGO) nanocomposites synthesized via the solvothermal method is presented. The microstructure and crystal morphology of the materials were characterized by X-ray diffractometer (XRD), X-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM), and transmission electron microscopy (TEM) analyses. Single crystalline hollow Fe₃O₄ spheres were grown onto RGO flakes, leading to the formation of heterojunction, which further influenced the microwave absorption properties. The latter were evaluated by standard microwave characterization in the frequency range of 2⁻18 GHz. It was found that, for a specific Fe₃O₄@0.125 g RGO composite, the minimum reflection loss can reach -41.89 dB at 6.7 GHz, while the reflection loss was less than -10 dB from 3.4 GHz to 13.6 GHz for a nanocomposite sample thickness in the range of 1⁻4 mm. The combination of these two materials thus proved to give remarkable microwave absorption properties, owing to enhanced magnetic losses and favorable impedance matching conditions.
磁性纳米颗粒，如Fe₃O₄和Co₃O₄，在先进微波吸收材料的研究中起着至关重要的作用，即便诸如高密度和窄带阻抗匹配等问题仍未得到解决。在此，介绍了通过溶剂热法合成的轻质空心Fe₃O₄@还原氧化石墨烯（RGO）纳米复合材料的研究。通过X射线衍射仪（XRD）、X射线光电子能谱（XPS）、扫描电子显微镜（SEM）和透射电子显微镜（TEM）分析对材料的微观结构和晶体形态进行了表征。单晶空心Fe₃O₄球生长在RGO薄片上，导致异质结的形成，这进一步影响了微波吸收性能。通过在2⁻18 GHz频率范围内的标准微波表征对后者进行了评估。结果发现，对于特定的Fe₃O₄@0.125 g RGO复合材料，在6.7 GHz时最小反射损耗可达-41.89 dB，而对于厚度在1⁻4 mm范围内的纳米复合材料样品，从3.4 GHz到13.6 GHz反射损耗小于-10 dB。因此，由于增强的磁损耗和良好的阻抗匹配条件，这两种材料的组合被证明具有卓越的微波吸收性能。
