Comparative morphological and crystallographic analysis of copper powders obtained under different electrolysis conditions

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 small 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.