NiO包覆Ni纳米颗粒的制备及其氧化特性研究

通过对直流电弧等离子体制备的Ni纳米颗粒钝化处理得到NiO包覆Ni纳米颗粒。并对试样的组成成分、形貌、晶体结构、粒度和氧化特性采用高分辨透射电子显微镜(HRTEM)、X射线衍射(XRD)、透射电子显微镜(TEM)和选区电子衍射(SAED)、热重和差示扫描量热分析仪(TGA/DSC)等手段进行分析。结果表明:经过表面钝化处理的NiO包覆Ni纳米颗粒具有明显的核-壳结构,内核为纳米Ni,外壳为NiO氧化物。颗粒呈球形,粒度均匀,分散性良好,粒径分布在20~70nm范围内,平均粒径为44nm,壳层氧化膜的厚度为5~8nm。壳核结构防止了纳米Ni颗粒的进一步氧化和团聚。

Study on Preparation and Oxidization Resistance of NiO Encapsulated Ni Nanoparticles

NiO encapsulated Ni nanoparticles were prepared by direct current arc plasma method and subsequently passivation.The chemical composition,morphology, crystal microstructure, particle size and oxidization resistance of the product were analyzed using the high-resolution transmission electron microscopy (HRTEM), X-ray diffraction (XRD), transmission electron microscopy (TEM) and the corresponding selected-area electron diffraction (SAED), thermogravimetric analyzer (TGA) and diffirential scanning calorimeter (DSC).The results showed that the NiO encapsulated Ni nanoparticles with clear core-shell structure.The core is consisted of particles of Ni,while the shell is consisted of NiO.The particle size of the samples was homogeneously distributed with spherical shape and well dispersed, the particle size distribution ranging from 20-70nm with the average particle size about 44nm and the thickness of the shell 5-8nm.The core-shell structure can prevent Ni nanoparticles from oxidation and agglomeration.