Synthesis and characterization of nickel nanoparticles by hydrazine reduction in ethylene glycol
Synthesis and characterization of nickel nanoparticles by hydrazine reduction in ethylene glycol
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DOI：
10.1016/s0021-9797(02)00135-2
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发表时间：
2003-03-15
影响因子：
9.9
通讯作者：
Chen, DH
中科院分区：
文献类型：
--
作者：
Wu, SH;Chen, DH
研究了在无可溶性高分子保护剂的条件下，以乙二醇为溶剂，在60 ℃下肼还原氯化镍制备纳米镍的方法。结果表明，适量的氢氧化钠溶液对纯镍纳米粒子的形成是必要的。另外，也不需要在氮气氛下进行反应。通过X射线衍射、高分辨透射电子显微镜和电子衍射图谱的分析，结果表明所制备的镍粒子为面心立方（fcc）结构的纯晶态镍。通过透射电镜观察发现，随着[N2 H5 OH]/[NiCl 2]比值的增加，平均粒径减小，当[N2 H5 OH]/[NiCl 2] > 12时，平均粒径趋于一个常数。此外，所得的镍纳米粒子可以磁性回收和再分散在乙二醇中没有尺寸变化和团聚。磁性测量表明，它们是超顺磁性的，饱和磁化强度为22 emu/g，相对磁化强度为6.4emu/g，平均粒径为9.2nm，磁化强度为0.1Oe。此外，由于热能的减少，磁化强度随着温度的降低而增加。所有观察到的磁性基本上反映了纳米颗粒的性质。此外，发现肼被所得的镍纳米颗粒催化分解成氢气和氮气。在25 ℃和1个大气压下的相应分解速率为3.1 nmol/（h mg Ni）。(C)2003 Elsevier Science（美国）。All rights reserved.
The synthesis of nickel nanoparticles by the hydrazine reduction of nickel chloride in ethylene glycol at 60 degreesC without soluble polymer as a protective agent was studied. It was found that an appropriate amount of NaOH was necessary for the formation of pure nickel nanoparticles. Also, it was not necessary to perform the reaction under a nitrogen atmosphere. By the analyses of X-ray diffraction, high-resolution transmission electron microscopy, and electron diffraction pattern, the resultant particles were characterized to be pure crystalline nickel with a face-centered cubic (fcc) structure. By transmission electron microscopy, it was observed that the mean diameter decreased with increasing the ratio of [N2H5OH]/[NiCl2] and approached a constant when [N2H5OH]/[NiCl2] > 12. In addition, the resultant nickel nanoparticles could be magnetically recovered and re-dispersed in ethylene glycol without size change and agglomeration. The magnetic measurements indicated they were superparamagnetic with a saturation magnetization of 22 emu/g, a remanent magnetization of 6.4 emu/g, and a coercivity of 0.1 Oe at a mean diameter of 9.2 nm. Also, the magnetization increased with decreasing temperature due to the decrease in thermal energy. All the observed magnetic properties essentially reflected the nanoparticle nature. Furthermore, it was found that hydrazine was catalytically decomposed to hydrogen and nitrogen gases by the resultant nickel nanoparticles. The corresponding decomposition rate at 25 degreesC and 1 atm was 3.1 nmol/(h mg of Ni). (C) 2003 Elsevier Science (USA). All rights reserved.