Streamlined Derivations and Explanations of the Scharifker-Hills Model

Despite being very popular in the analysis of experimentally measured potentiostatic transients during the initial stage of electrodeposition of metallic single-element coatings, the derivations and the assumptions of the Scharifker-Hills (S-H) model are not well understood. Important details and assumptions are scattered in different original papers. Meanwhile, some of the simplifications in derivations are somewhat intuitive, rather than being rigorously derived from a set of governing equations. It is important to understand the derivations, the assumptions, and the successfulness of the S-H model first before moving forward to an advanced model for the potentiostatic transient at the initial stage of metal or alloy electrodeposition. In this presentation, we will provide rigorous derivation for each step and each assumption, thus achieving a complete demonstration of the physics of the S-H model. References: [1] G.J. Hills, D.J. Schiffrin, J. Thompson, Electrochemical nucleation from molten salts—I. Diffusion controlled electrodeposition of silver from alkali molten nitrates, Electrochim. Acta, 19 (1974) 657-670. [2] B. Scharifker, G. Hills, Theoretical and experimental studies of multiple nucleation, Electrochim. Acta, 28 (1983) 879-889. [3] G. Gunawardena, G. Hills, I. Montenegro, B. Scharifker, Electrochemical nucleation: Part I. General considerations, J. Electroanal. Chem., 138 (1982) 225-239. [4] B.R. Scharifker, J. Mostany, Three-dimensional nucleation with diffusion controlled growth: Part I. Number density of active sites and nucleation rates per site, J. Electroanal. Chem., 177 (1984) 13-23. [5] B.R. Scharifker, J. Mostany, Electrochemical Nucleation and Growth, in: A.J. Bard (Ed.) Encyclopedia of Electrochemistry2007, pp. 512-539. [6] M. Sluyters-Rehbach, J.H.O.J. Wijenberg, E. Bosco, J.H. Sluyters, The theory of chronoamperometry for the investigation of electrocrystallization: Mathematical description and analysis in the case of diffusion-controlled growth, J. Electroanal. Chem., 236 (1987) 1-20.