【摘要】 研究不同析氢条件下恒电位电解法制备铜粉的过程。采用扫描电镜(SEM)、X射线衍射(XRD)、粒度分布(PSD)和比表面积测定(SSA)对铜粉进行表征。根据电解过程析氢量的大小,形成树枝状和菜花状两种类型的颗粒。当析氢量大到足以对近电极层中的流体动力学条件产生强烈影响时,形成菜花状颗粒,否则形成树枝状颗粒。虽然颗粒的宏观结构差异很大,但他们的微观结构却相似,也就是说,这两种颗粒在微观层面上都是由近似球形的Cu颗粒小团聚体组成;球状形貌的存在是造成两种颗粒中Cu晶粒随机取向的原因。菜花样颗粒的比表面积是树枝状颗粒的3倍以上,其粒径则比树枝状颗粒的小很多。由此可见,强析氢条件对于铜粉制备是有益的。更多还原

【Abstract】 Production of copper powders by the potentiostatic electrolysis under different hydrogen evolution conditions was investigated. Copper powders were characterized by the scanning electron microscope(SEM),X-ray diffraction(XRD),particle size distribution(PSD), and by the determination of the specific surface area(SSA) of the formed powders. Depending on quantity of hydrogen generated during electrolysis, the two types of particles were formed: dendrites and cauliflower-like particles. The dendrites were formed without, while cauliflower-like particles with the quantity of evolved hydrogen enough to achieve strong effect on hydrodynamic conditions in the near-electrode layer. Although macro structure of the particles was very different, they showed similar micro structure. Namely, both types of the particles consisted of smalal agglomerates of approximately spherical Cu grains at the micro level. The existence of the spherical morphology was just responsible for random orientation of Cu crystallites in both types of particles. The SSA of cauliflower-like particles was more than two times larger than that of the dendrites, while their size was considerably smaller than that of the dendritic particles. In this way, the useful benefit of Cu powder formation in the conditions of vigorous hydrogen evolution is shown.更多还原