Electrochemical quartz-crystal microbalance study of silver and copper electrodeposition on bare and iodine-covered platinum electrodes

Electrodeposition of silver and copper on iodine-covered and bare polycrystalline Pt electrodes is studied with the electrochemical quartz-crystal microbalance (EQCM). Voltammetry of silver on the iodine-covered surface shows single deposition and stripping peaks, with masses appropriate for silver. This is an ideal calibration system, because similar interactions are present between the electrolyte and the iodine atoms in the presence and absence of silver. This system was used as a reference point to interpret the deviations from ideal mass that occur in the absence of iodine. In the absence of iodine, four distinct deposition and stripping regions are observed. A lower mass than the ideal silver mass for multilayer silver electrodeposition was attributed to smoothening of the electrode. A comparative study of the analogous copper system is also reported. (C) 2004 Elsevier B.V. All rights reserved.