碳包覆氧化镍纳米颗粒的制备与电化学性能

Preparation and Electrochemical Performance of Carbon-encapsulated NiO Nanoparticles

采用直流电弧放电等离子体技术制备了核壳结构碳包覆氧化镍纳米颗粒,并采用X射线衍射、高分辨透射电子显微镜、X射线能量色散分析谱仪和表面物理吸附仪等测试技术对样品的微观结构进行研究。并利用循环伏安法、恒电流充放电以及交流阻抗等技术研究其作为超级电容器电极材料的电化学性能。结果表明:直流电弧等离子体技术制备的碳包覆氧化镍纳米颗粒具有典型的核壳结构,内核为面心立方结构的氧化镍纳米颗粒,外壳为碳层。颗粒形貌主要为立方体结构,粒度均匀,分散性良好,粒径分布在30～70 nm范围,平均粒径为50 nm,外壳碳层的厚度为5 nm。碳包覆氧化镍纳米颗粒具有较高的比容量和良好的电化学活性。

The core shell structure carbon-encapsulated NiO nanoparticles were prepared by DC arc discharging plasma technology. The microstructure of the samples were studied by X-ray diffraction(XRD), high resolution transmission electron microscopy(HRTEM), X-ray energy dispersive spectrometry(EDS) and surface physical adsorption. The electrochemical performances of the composites as the electrode materials for super-capacitors were investigated by cyclic voltammetry, galvanostatic charging-discharging and electrochemical impedance spectroscopy. The results indicate that the carbon-encapsulated NiO nanoparticles prepared by DC arc plasma technology possess typical core shell structure, the core of the particles is NiO with face centered cubic structure, and the outer shell is disordered carbon layer. The particle morphology exhibit cube structure with uniform particle size and good dispersion. The particle size distribution is in the range of 30~70 nm, the average particle size is 50 nm, and the thickness of the carbon shell is about 5 nm. The carbonencapsulated NiO nanoparticles has high specific capacity and good electrochemical activity.