纺锤状ZnO/还原氧化石墨烯异质结构及其微波吸收性能

Microwave Absorption Performance of Spindle-Shaped ZnO/Reduced Graphene Oxide Heterostructure

目的调节石墨烯的电磁匹配,以实现最优的微波吸收性能。方法通过改进的Hummers法制备氧化石墨烯GO,以六水合硝酸锌、双六甲撑三胺、氧化石墨烯为原料,采用水热法在140℃获得了具有异质结构的包裹r-GO的纺锤状ZnO棒(S-ZnO/r-GO)。通过X射线衍射分析仪(XRD)、扫描电子显微镜(SEM)以及透射电子显微镜(TEM)测试,分别对S-ZnO/r-GO的组成成分、形貌特征以及微观结构进行了表征,同时采用同轴法,通过矢量网络分析仪测试分析了不同填充浓度下S-ZnO/r-GO复合材料在2~18 GHz范围内的电磁特性,并通过计算得到了材料的微波反射率损耗。结果尺寸均匀且相互交织的纺锤状ZnO棒被大量褶皱的还原氧化石墨烯所包覆,构建了一种相互连接的三维交织结构。纺锤状ZnO的引入以及三维结构的建立,明显改善了S-ZnO/r-GO异质结构在2~18 GHz频率范围内的电磁特性和微波响应。在厚度为2.0 mm,频率为14.8 GHz处,最大反射率损耗值达到−40 dB,有效吸收带宽几乎覆盖整个Ku波段。结论纺锤状ZnO/r-GO复合材料表现出优异的微波吸收性能和较宽的有效吸收频段,具有一定的应用前景。

This work aims to adjust the electromagnetic matching of graphene to achieve the best microwave absorption performance.Graphene oxide was prepared by improved Hummers method.The spindle-shaped ZnO rods wrapped by reduced graphene oxide(S-ZnO/r-GO)with heterostructure were synthesized by the hydrothermal method at 140℃with Zinc nitrate hexahydrate,bis-hexamethylene triamine and graphene oxide as raw materials.The composition,morphology and microstructure of S-ZnO/r-GO were characterized by X-ray diffractometer(XRD),scanning electron microscope(SEM)and transmission electron microscopy(TEM).The electromagnetic properties of S-ZnO/r-GO composite with different mass ratios were tested by vector network analyzer in the frequency range of 2~18 GHz through coaxial method,and the microwave reflection loss of the composite was calculated.The interlaced spindle-shaped ZnO rods with uniform shapes were wrapped with plenty crumpled r-GO sheets,thus constructing an interconnected 3D structure.Both the introduction of spindle-shaped ZnO and the construction of 3D structure significantly improved the electromagnetic characteristics and microwave response of S-ZnO/r-GO heterostructure in the frequency range of 2~18 GHz.A maximum reflection loss value of−40 dB was achieved at a thickness of 2.0 mm and a frequency of 14.8 GHz.The effective absorption bandwidth almost covered the whole Ku band.The composites of S-ZnO/r-GO exhibit prominent microwave absorption performance and wide effective absorption bandwidth and have certain application prospects.