Publication details
Application of elimination voltammetry with linear scan to the study of electrode processes on a graphite electrode
| Authors | |
|---|---|
| Year of publication | 2006 |
| Type | Article in Proceedings |
| Conference | Sborník příspěvků VI. Pracovního setkání fyzikálních chemiků a elektrochemiků |
| MU Faculty or unit | |
| Citation | |
| Field | Electrochemistry |
| Keywords | elimination voltammetry with linear scan; electrode processes; graphite electrode |
| Description | Introduction The solid electrodes in general, and the carbon materials (powder, fiber or glassy carbon) in particular, have been used widely in electroanalytical research and technological applications (functional or structural fuel cell components). Carbon materials have played an important role in solid electrode development for the following reasons. First, various forms are available at reasonable price. Second, the slow kinetics of carbon oxidation leads to a wide useful potential range. The carbon electrode can be modified by applying a thin metallic or polymer layer, or in case of the paste electrode by some additives or powders (graphite composite electrode) that increase the selectivity [1]. This contribution describes the voltammetric results of some depolarizers on a paraffin impregnated graphite electrode (PIGE). The graphite rod of spectral purity is a porous material and, therefore, must be impregnated with paraffin to fill the pores and decrease the background current [2]. The disadvantages of PIGE and/or all solid electrodes lie in the necessity of their mechanical regeneration and electrical activation of the surface. In this contribution we have focused on the interpretation of electrochemical processes (Cd2+/Cd, Ni2+/Ni, Cu2+/Cu) on PIGE in various solutions (Cl-, SO42-, NO3-, H3BO3) by using voltammetric methods (CV, LSV) including elimination voltammetry with linear scan (EVLS). The elimination procedure is based on the fact that the total voltammetric current responses recorded consist of a set of particular currents, e.g. charging, diffusion, and kinetic currents. The EVLS enables selected particular currents to be eliminated and unknown processes to be revealed [3-6]. Conclusion The graphite electrode (PIGE) is suitable for the study of reduction processes of metals (Cd, Cu, Ni) using voltammetric methods (CV, LSV). During deposition processes the elimination voltammetry (E4 function) revealed the Ipp peak. This peak reflects certain surface reaction controlled by kinetic (e.g. sorption, surface diffusion, nucleation). |
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