磁性金属镍纳米管的有效合成

以多孔氧化铝为模板, 三嵌段共聚物F127(EO108PO69EO108, EO: ethylene oxide, PO: propylene oxide)为添加剂, 采用电化学沉积技术, 制备了高度有序的磁性金属镍纳米管阵列. 该合成方法简单、有效、易操作, 特别是, 氧化铝模板的孔壁不需要进行任何修饰. 通过透射电子显微镜(TEM)、扫描电子显微镜(SEM)、X射线衍射(XRD)和振动样品磁强计(VSM)对产物的形貌、结构和磁学性质进行表征. X射线衍射(XRD)分析表明, 产物的晶型结构为面心立方. 利用透射电子显微镜研究了实验参数, 如电流密度、共聚物浓度和电沉积时间, 对产物形貌的影响, 结果表明, 镍纳米管的管壁厚度随着电流密度增大和电沉积时间的延长而变大, 但几乎不受F127浓度变化的影响. 以上的实验表明, 调节实验参数, 可以有效控制纳米管管壁的厚度. 磁性研究结果表明, 与块体镍相比较, 镍纳米管阵列表现出较大的矫顽力.

Effective Synthesis of Magnetic Metal Nickel Nanotubes

Using porous anodic alumina(PAA)as the template,we fabricated a highly ordered array of magnetic metal nickel nanotubes by adding the tri-block copolymer F127(EO108PO69EO108,EO:ethylene oxide,PO:propylene oxide)in a common electrolyte solution and by using electrodeposition technique.This synthetic method is very easy,effective and facile.Especially,the pore wall of the template does not need to be modified.The morphology,structure and magnetic property of the product were characterized by transmission electron microscopy(TEM),scanning electron microscopy(SEM),X-ray diffraction(XRD)and vibrating sample magnetometry(VSM).The face-centered cubic(fcc)structure of nickel was confirmed by X-ray diffraction(XRD).We investigated the effects of experimental parameters such as the electric current density,the concentration of copolymer and electrodeposition time on product morphology by transmission electron microscopy (TEM).Experimental results showed that the wall of nickel nanotubes thickened as current densities and deposition time increased,but the wall thickness was hardly influenced by a change in the concentration of F127.Based on these experimental results,we could control the wall thickness of the nanotubes by adjusting experimental parameters.Magnetic measurements on the array of Ni nanotubes indicated an enhanced coercivity compared to bulk nickel.