标题:
Fe3O4纳米微球、MWCNT/Fe3O4异质结构溶剂热制备和微波吸收性能Solvothermal Synthesis and Microwave Absorbing Properties of Fe3O4Microspheres and MWCNT/Fe3O4Heterostructures
作者:
郭长发, 苏庆梅, 杜高辉, 胡勇
关键字:
Fe3O4, 碳纳米管, 异质结构, 微波吸收Fe3O4; Carbon Nanotubes; Heterostructures; Microwave Absorbing
期刊名称:
《Material Sciences》, Vol.1 No.2, 2011-07-29
摘要:
以六水氯化铁、无水乙酸钠和乙二醇为原料，采用溶剂热法制备了尺寸均一的Fe3O4纳米微球。在反应体系中掺入多壁碳纳米管(MWCNTs)并通过改变其用量进而制备了一系列链状MWCNT/Fe3O4异质结构。利用扫描电子显微镜(SEM)和X-射线衍射仪(XRD)对Fe3O4纳米微球和MWCNT/Fe3O4异质结构进行形貌和晶相分析。结果表明Fe3O4纳米微球有明显的层级结构，在异质结构中不连续地镶嵌在MWCNTs表面，且镶嵌密度随MWCNTs用量的减少而增大。MWCNTs的掺入对Fe3O4纳米微球的晶相没有影响，但组成微球的颗粒变得更小。用N5230A型网络矢量分析仪测试两者在2～18 GHz的微波吸收性能。结果显示Fe3O4纳米微球有明显的微波吸收性能，且吸收频率区间和最大吸收峰随涂层厚度增加向低频移动。相比之下，MWCNT/Fe3O4异质结构的微波吸收能力在低频明显降低，而在高频有所增强。
Fe3O4 microspheres were prepared via a facile solvothermal method using hydrous ferric chloride and anhydrous sodium acetate as materials, and ethylene glycol as solvent. Furthermore, the tunable denseness carbon nanotubes (MWCNTs)/Fe3O4 heterostructures were obtained by adjusting the ratio of ferric chloride and MWCNTs in the reaction system. The morphology and phase of the products were characterized by scanning electron microscope (SEM) and X-ray diffractometer (XRD). The results show that Fe3O4 microspheres with hierarchical structure wrap discontinuously on MWCNTs in the hybrids, and wrapping density increase with reduction of the amount of MWCNTs. The Fe3O4 microspheres with an unchanged phase in the heterostructures are composed of smaller particles after addition of MWCNTs than before. In addition, microwave absorbing properties of Fe3O4 microspheres and MWCNT/Fe3O4 heterostructures were measured at a microwave frequency range of 2 - 18 GHz with an N5230A vector network analyzer, and the results indicated that Fe3O4 microspheres obviously possessed the ability of microwave absorption and the strongest absorbing peak shifted to lower frequency with the coating thickness increase. Compared to Fe3O4 microspheres, MWCNT/Fe3O4 heterostructures tend to absorb microwave at higher frequency and weaken absorption at lower frequency.