高度有序C基金属氧化物材料的制备及吸波性能

发布时间：2018-05-22 14:08

本文选题：氧化锌 + 碳基　；参考：《沈阳工业大学》2017年硕士论文

【摘要】：本文采用溶剂热法得到了金属有机骨架化合物MOF-5,用其作为前驱物,在氮气下热处理得到ZnO/C复合材料;采用溶剂热法制备Fe~(3+)掺杂MOF-5,热处理后成功得到ZnO/ZnFe_2O_4/C复合吸波材料。利用X射线衍射仪(XRD)、扫描电镜(SEM)、傅里叶转换红外光谱分析仪(FTIR)、振动样品磁强计(VSM)和矢量网络分析仪(VNA)等对所制样品的物相、微观结构、磁性及吸波性能进行了分析。SEM图像分析表明,所制备的ZnO/C材料粒径大小约为25μm,是完全由片状物堆叠起来的完整的立方体结构,薄片厚度约为20nm,且Zn、O、C各元素均匀分布。由FTIR图谱分析可知,ZnO/C复合材料在6-8μm、23-24μm处有两个红外吸收峰,吸波率分别约为45%、65%左右;由微波吸收性能研究表明,最佳反射损耗在17.18GHz处时达-14.1dB,相对的应厚度为7mm,其频带宽为16.8GHz-17.67GHz;此外,Fe~(3+)掺杂的MOF-5做为前驱物,对热处理后得到的ZnO/ZnFe_2O_4/C复合吸波材料进行检测:SEM结果表明,ZnO/ZnFe_2O_4/C为的多孔中空蜂窝状结构的立方体形态,粒径约为25-30μm;由磁性能分析可知,在室温条件下,ZnO/ZnFe_2O_4/C复合材料为顺磁-超顺磁性能,其饱和磁化强度约为8emu/g,剩余磁化强度(Mr)约为2emu/g,矫顽力(Hc)约为2.13KA/m;由红外光谱图分析得知,ZnO/ZnFe_2O_4/C复合材料在6-7μm、18-19μm、23-24μm处有三个很强的红外吸收峰,吸波率分别为70%、83%、89%;由微波吸收性能研究表明,ZnO/ZnFe_2O_4/C复合材料在涂层厚度为7.5-7.9mm时均有对电磁波小于-10dB的衰减,所对应的吸波频带是14.62-16.05GHz。最大反射率出现在14.5GHz处可达-13.98dB,对应厚度为7.6mm。研究表明本文设计合成ZnO/C材料,其质量轻、比表面积大,且多孔结构造成多重散射,这些散射和电子极化、界面极化、驰豫作用均增加了材料对电磁波的吸收和衰减,增强了吸波性能。掺杂Fe~(3+)后得到的ZnO/ZnFe_2O_4/C复合吸波材料不仅具有ZnO/C材料多孔中空的孔道结构特性而且还改善了电磁参数,使其在微波吸收性能良好的基础上拓宽吸收频带宽度以及进一步提高了红外吸收率。
[Abstract]:In this paper, a solvothermal method was used to obtain a metal organic skeleton compound MOF-5, which was used as a precursor to get ZnO/C composite under nitrogen heat treatment. Fe~ (3+) doped MOF-5 was prepared by solvent heat method. After heat treatment, the ZnO/ZnFe_2O_4/C composite absorbing material was successfully obtained. Using X ray diffractometer (XRD), scanning electron microscopy (SEM), Fourier transform red An external spectral analyzer (FTIR), a vibrating sample magnetometer (VSM) and a vector network analyzer (VNA) were used to analyze the phase, microstructure, magnetic properties and absorption properties of the samples. The analysis of.SEM images showed that the size of the prepared ZnO/C material was about 25 u m, and the complete cube structure and thin slice thickness were completely stacked by the sheet. The degree is about 20nm, and the elements of Zn, O and C are evenly distributed. From the FTIR map analysis, the ZnO/C composite has two infrared absorption peaks at 6-8 mu m and 23-24 mu m, and the absorption rate is about 45% and 65%, respectively. The optimum reflection loss is -14.1dB with the relative thickness of 16.8GHz-17, and the frequency bandwidth is 16.8GHz-17. In addition, Fe~ (3+) doped MOF-5 was used as a precursor to detect the ZnO/ZnFe_2O_4/C composite absorbing material obtained after heat treatment. The SEM results showed that the cubic shape of the porous hollow honeycomb structure of ZnO/ZnFe_2O_4/C was about 25-30 u m, and the magnetic properties showed that at room temperature, the ZnO/ZnFe_2O_4/C composite material was at room temperature. The paramagnetic and superparamagnetic properties are about 8emu/g, the residual magnetization (Mr) is about 2emu/g and the coercive force (Hc) is about 2.13KA/m. By the analysis of infrared spectra, there are three strong infrared absorption peaks of ZnO/ZnFe_2O_4/C composites at 6-7 mu m, 18-19 u m and 23-24 u m, and the absorption properties of microwave absorption are 70%, 83%, 89%, respectively. It is shown that the ZnO/ZnFe_2O_4/C composite has the attenuation of the electromagnetic wave less than -10dB when the coating thickness is 7.5-7.9mm. The corresponding absorption band is the maximum 14.62-16.05GHz. reflectivity at 14.5GHz to -13.98dB. The corresponding thickness of 7.6mm. study shows that the ZnO/ C material is designed and synthesized in this paper, which is light, larger than surface area and porous junction. It is constructed into multiple scattering. These scattering and electron polarization, interfacial polarization and relaxation increase the absorption and attenuation of the electromagnetic wave and enhance the absorption properties. The ZnO/ZnFe_2O_4/C composite absorbing material obtained after doping Fe~ (3+) not only has the pore structure characteristics of the porous hollow ZnO/C material but also improves the electromagnetic parameters, so that the electromagnetic parameters are also improved. On the basis of good microwave absorption properties, broadening the absorption band width and further improving the infrared absorption rate.
【学位授予单位】：沈阳工业大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TB34

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