石墨烯装载不同含量钴锌铁氧体及其电磁行为对比

以天然鳞片石墨为原料制备氧化石墨(GO), 应用水热法制备钴锌铁氧体(Co_0.5Zn_0.5Fe₂O₄), 并将两者制备成石墨烯(rGO)/Co_0.5Zn_0.5Fe₂O₄复合材料。采用X射线衍射(XRD)、拉曼光谱(Raman)、红外光谱(FT-IR)研究rGO/Co_0.5Zn_0.5Fe₂O₄的结构; 应用透射电子显微镜(TEM)和矢量网络分析仪(VNA)研究不同复合比例对rGO/Co_0.5Zn_0.5Fe₂O₄复合材料形貌、电磁损耗特性、德拜弛豫模型及电磁响应行为的影响。结果表明: 复合反应后的GO在XRD图谱中主衍射峰由2θ=9.74°变化为2θ=24.15°, 且红外光谱图中显示含氧官能团消失, 均说明GO成功还原为rGO。透射电子显微镜图中可以看到Co_0.5Zn_0.5Fe₂O₄嵌布在rGO上。复合反应过程中, 当钴锌铁氧体的含量增大, 分散性逐渐减弱。Co_0.5Zn_0.5Fe₂O₄与GO质量比为2 : 1时制备的rGO/Co_0.5Zn_0.5Fe₂O₄复合材料的吸波性能最佳, 在15.11 GHz处反射率达到最小值-36.89 dB, 有效吸波频带宽为3.74。

Comparison of Electromagnetism Behavior of Different Content Cobalt-zinc Ferrite Loaded with Graphene

A kind of graphene composite (rGO/Co_0.5Zn_0.5Fe₂O₄) was synthesized with the graphene oxide (GO) prepared from natural flake graphite and cobalt-zinc ferrite (Co_0.5Zn_0.5Fe₂O₄) manufactured by the hydrothermal method. The structure of composites was characterized by X-ray diffraction (XRD), Raman spectrometer (Raman) and the Fourier-transform infrared spectroscopy (FT-IR). Morphology, electromagnetic loss properties, Debye relaxation, and microwave absorbing properties of rGO/Co_0.5Zn_0.5Fe₂O₄ were investigated by transmission electron microscope (TEM) and vector network analyser (VNA). Sharp peak of graphene oxide was changed from 2θ=9.74° to 24.15° in the XRD patterns and the oxygen functional group disappeared after the composite reaction, which demonstrated that GO was successfully reduced to rGO. The graphene was embedded with cobalt-zinc ferrite, observed by transmission electron microscope, with its dispersion worse with the loaded Co_0.5Zn_0.5Fe₂O₄ increasing. Absorbing property of rGO/Co_0.5Zn_0.5Fe₂O₄ composite prepared with w(Co_0.5Zn_0.5Fe₂O₄) : w(GO)= 2 : 1 is the best with the minimum reflectivity of -36.89 dB at 15.11 GHz and the effective absorption frequency bandwidth of 3.74.