Electrochemistry of tin deposition from mixed sulphate and methanesulphonate electrolyte

Abstract

The electrodeposition of tin, at a copper surface, from a tin sulphate (0˙014 mol dm–3) electrolyte containing methanesulphonic acid (12 ˙5 vol.-%) at 295 K has been studied. Cyclic voltammetry, using potential sweep rates of 8–128 mV s–1, at a stationary copper electrode provided information on the potential ranges for tin deposition and stripping. Linear sweep voltammetry, at a copper rotating disc electrode was used to evaluate the mass transport characteristics of the system under controlled, laminar flow conditions. The changes in the limiting current density with a Sn2+ concentration of 0˙006–0˙078 mol dm–3 and an electrode rotation rate of 200–4800 rev min–1 were quantified. Randles-Sevčik and Levich equations were used to give an averaged diffusion coefficient for Sn2+ of 5˙4 × 10–6 cm2 s–1.