Comparative Morphological and Crystallographic Analysis of Electrochemically- and Chemically-Produced Silver Powder Particles

Abstract

Silver powders chemically synthesized by reduction with hydrazine and those produced by electrolysis from the basic ( nitrate) and complex ( ammonium) electrolytes were examined by X-ray diffraction (XRD) and scanning electron microscopic (SEM) analysis of the produced particles. Morphologies of the obtained particles were very different at the macro level. The needle-like dendrites, as well as the mixture of irregular and regular crystals, were formed from the nitrate electrolyte, while the highly-branched pine-like dendrites with clearly noticeable spherical grains were formed from the ammonium electrolyte. The agglomerates of spherical grains were formed by reduction with hydrazine. In the particles obtained from the nitrate electrolyte, Ag crystallites were strongly oriented in the (111) plane. Although morphologies of Ag particles were very different at the macro level, the similarity at the micro level was observed between chemically-synthesized particles and those obtained by electrolysis from the ammonium electrolyte. Both types of particles were constructed from the spherical grains. This similarity at the micro level was accompanied by the similar XRD patterns, which were very close to the Ag standard with a random orientation of Ag crystallites. For the first time, morphologies of powder particles were correlated with their crystal structure.