Structural investigation of the initial stages of copper electrodeposition on polycrystalline and single crystal palladium electrodes

• Published in: Electrochimica acta 1990-07, Vol.35 (7), p.1189-1194
• Main Authors: Rigano, P.M., Mayer, C., Chierchie, T.
• Format: Article
• Language: English
• ISSN: 0013-4686; 1873-3859
• DOI: 10.1016/0013-4686(90)80038-P

The electrodeposition of Cu on polycrystalline and single crystal Pd electrodes has been studied by combining electrochemical techniques with optical ones. On Pd(111) the deposition process begins with the formation of quasi-two-dimensional Cu crystallites which transform into three-dimensional truncated pyramids with increasing deposition time. On Pd(100) a multilayer process is observed together with a pyramidal outgrowth on the top of the underlying layers. The morphology of deposits on the polycrystalline substrate, depends strongly on the surface pretreatment. On mechanically polished electrodes Cu crystallites, some of them with well defined geometric shapes, are observed all over the surface. On the contrary, on electrochemically polished substrates different grains appear on the surface. Depending on the crystallographic orientation of each grain, Cu deposits as those described for Pd(111) and Pd(100) are observed. This indicates that the polycrystalline material is composed mainly of long range order regions possessing a (111) and a (100) orientation, in agreement with the results obtained by comparing the behaviour of each substrate within the underpotential deposition range.