Simultaneous underpotential deposition of lead and thallium on polycrystalline silver-III

Simultaneous underpotential deposition of lead and thallium from a tartrate medium on a polycrystalline silver electrode is reported. Results of cyclic voltammetric investigations of the effects of concentration and sweep rate on the codeposition behaviour are discussed. Further investigations of the codeposition behaviour through voltammetric experiments using programmed potential inputs are described and discussed in terms of formation of a two-dimensional alloy. Finally, the validity of the existing models of electrochemical phase formation has been investigated under the codeposition conditions.Nomenclature I _pn nondimensional peak current - E _pn nondimensional peak potential - E _/12n nondimensional half-peak width - Q _M charge due to UPD coverage of metal M (Ccm^–2) - t _d holding time (s) - sweep rate (V s^–1) - E potential (V) - instantaneous nucleation growth rate constant