Elimination Voltammetry - An Attractive Method for the Evaluation
of Electrochemical Processes
Xiaochun Li*1
, Libuse Trnkova1
, Jan Cechal2
, Iveta Triskova1
1
Department of Chemistry, Faculty of Science, Masaryk University, Kamenice 5, 625 00 Brno
2
Brno University Technology, CEITEC, Purkynova 123, 61200, Brno
*517716@mail.muni.cz
Elimination voltammetry with linear scan (EVLS) is a methodologically new tool for processing
voltammetric data in order to obtain more detailed information about the studied
electrochemical processes[1]. EVLS processes the records of a linear sweep or cyclic
voltammetry into the form of elimination functions, which eliminate some selected current
components and preserve others. The impetus for this research was the idea, based on the fact
that if the EVLS was applied for a reversible system, then the function preserving only the
kinetic current component (E5) or only the capacitive component (E6) with the elimination of
the diffusion current component should correspond to the zero current lines[2]. In a common
three-electrode arrangement, the current-voltage responses required for EVLS are sensed at the
working electrode[3]. In our experiments, the working electrode was represented by a pencil
graphite electrode (PeGE) with excellent electrode properties, such as thermal and mechanical
stability, low capacitance (charging) current, and high electron transfer rate[4]. It is easily
available, cheap, and therefore disposable. Compared to other working electrodes used in
voltammetric techniques, it provides more reproducible results. However, graphite pencil leads
of different brands can differ from each other and show different electrochemical behavior. We
found the best electrochemical activity with the polymer pencil electrode (pPeGE, Tombow) [5].
The validity of our presumptions was investigated by using the reversible probe [Fe(CN)6]3-/4on
two types of pPeGEs (Tombow from Japan and Staedtler from Germany) which were
characterized by X-ray photoelectron spectroscopy (XPS) and electrochemical impedance
spectroscopy (EIS). In order to learn more about the composition of their surfaces, the pencil
electrodes were exposed to chloroform. Deviations of the experimental EVLS functional records
from the theoretical calculation (zero currents for E5 and or E6) are discussed. A number of
eliminations were performed under different experimental conditions, and the greatest attention
was paid to EVLS E6, which preserves the capacitive current component and sensitively reflects
changes in the capacitance of the electric double layer[5]. The study shows that by using the
EVLS results, we are able to uncover extra information about voltammetric signals that are
hidden by the CV responses.
ACKNOWLEDGEMENT
The financial support provided by MU project: Development of methods and instrumentation for the
analysis of biologically important substances (MUNI/A/1539/2021 and MUNI/A/1421/2022).
REFERENCES
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Electroanalytical Chemistry, 582 (2005) 258-266.
[2] O. Dracka, Theory of current elimination in linear scan voltammetry, Journal of Electroanalytical
Chemistry, 402 (1996) 19-28.
[3] R. Navratil, A. Kotzianova, V. Halouzka, T. Opletal, I. Triskova, L. Trnkova, J. Hrbac, Polymer lead
pencil graphite as electrode material: Voltammetric, XPS and Raman study, Journal of Electroanalytical
Chemistry, 783 (2016) 152-160.
[4] L. Trnkova, I. Triskova, J. Cechal, Z. Farka, Polymer pencil leads as a porous nanocomposite graphite
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