Zinc Electrodeposition on Polycrystalline Copper: Electrochemical Study of Early-Stage Growth Mechanism

The early stage growth mechanism of zinc clusters electrodeposited on polycrystalline copper is studied by electrochemical methods. By analyzing the chronoamperometric and chronocoulometric data, nucleation and growth of the Zn layer as a function of time are investigated, and a growth model is proposed and discussed. Experimental and theoretical details about chronocoulometric data reveal a three-step growth mechanism. The results provide insights into the mechanism of electrodeposition of metallic particles. The same analysis process can also be described as the stripping mechanism. The formation and stripping mechanisms of a zinc adlayer can be predicted considering the contribution of four different processes: a Langmuir-type adsorption/desorption process, the two-dimensional nucleation and growth in instantaneous and progressive cases, and a three-dimensional nucleation and growth process under diffusion-limited condition.