R. KOwALIK*,# AnAlysIs of the underpotentIAl deposItIon of cAdmIum on copper AnAlizA procesu podpotencjAłowego osAdzAniA kAdmu nA miedzi

The underpotential deposition(UPD) phenomena is very interesting not only because of its fundamental importance but also due to its noticeable growing impact on the material science. The amazing possibility of control the deposition process down to monolayer results in new kind of materials with different properties than bulk ones embracing they catalytic, electronic or magnetic properties. Excellent reviews embracing theoretical considerations and different UPD systems are given in[1-5]. The systems related with cadmium attracted in the last years due to their application in the electrochemical atomic layer epitaxy (ECALE) process[6-9] and synthesis semiconductor compounds[10]. Moreover the modification of electrode surfaces through underpotential deposition enables to improve their catalytic properties, like in case a Cd-Au system[11, 12]. It also play a crucial role in the deposition of alloy coatings by electrochemical method[13]. Up-to-date, only few papers analyzed the problem of Cd UPD on Cu[13-19]. The formation of Cd UPD layer on Cu has been analyzed by conventional electrochemical techniques: cyclic voltammetry and potentiostatic measurements. Additionally the structural studies were carried out by X-ray photoelectron spectroscopy (XPS), low energy ion scattering (LEIS,) low energy electron diffraction (LEED), atomic force microscopy(AFM) and scanning tunneling microscopy (STM). The aim of this work was to study the process of deposition of cadmium on polycrystalline copper electrode in sulfate solution. The process of underpotential and bulk deposition was analyzed by classical electrochemical method: anodic stripping voltammetry(ASV), cyclic voltammetry(CV) and electrochemical quartz crystal microbalance(EQCM). The obtained results were compared with electrochemical impedance spectroscopy(EIS) measurements. The last technique indicates the range of potentials where underpotential and bulk deposition occurred. The obtained results are in very good accordance with previous ones obtained by ASV, CV and EQCM. A R C H I V E S O F M E T A L L U R G Y A N D M A T E R I A L S