基于核壳结构Co3Fe7@C的高效微波吸收材料

摘要

To reduce the density of the absorbent Co3Fe7,a core-shell Co3Fe7@C microwave absorbent was synthesized by preparing an iron/cobalt-containing carbon precursor followed by high-temperature carbonization.According to the X-ray diffraction (XRD) and transmission electron microscopy (TEM) results,Co3Fe7 particles were coated with graphitized carbon layers to form a core-shell structure.Furthermore,the Co3Fe7@C composite with a surface area and density of 358.5 m2·g-1 and 2.25 g·cm-3,respectively,exhibited excellent microwave absorbability.A minimum reflection loss (RL) of-43.5 dB and an effective bandwidth (RL below-10 dB) of 4.1 GHz were obtained at the coating thickness of 2 mm,which could be mainly attributed to the effective impedance match and multiple interfacial polarizations.Owing to the low density and remarkable microwave absorption,we believe that the Co3Fe7@C composite can be a promising candidate for use as a lightweight and efficient microwave absorbent.%为了降低吸波剂Co3Fe7的密度,本文采用原位聚合Fe3+-Co2+/碳前驱体及高温碳化制备得到Co3Fe7@C复合微波吸收材料.X射线衍射(XRD)和扫描电子显微镜(SEM)测试结果表明Co3Fe7颗粒被石墨碳层包覆形成核壳结构,复合物的比表面积和表观密度分别为358.5 m2·g-1、2.25 g·cm-3.核壳结构Co3Fe7@C复合物显示出优异的微波吸收性能,当涂层厚度为2 mm时,其最低反射损耗(RL)达到最低值-43.5 dB,对应的有效带宽为4.1 GHz,归因于复合物有效的阻抗匹配特性及多重界面极化效应.由于低密度及优异的微波吸收性能,Co3Fe7@C复合物有望作为一种潜在的轻质、高效微波吸收材料.