D 2016

Elimiantion Voltammetry with Potential Shift

TRNKOVÁ, Libuše

Basic information

Original name

Elimiantion Voltammetry with Potential Shift

Authors

Edition

1. vyd. Hague, 67th Annual Meeting of the International Society of Electrochemistry, 1 pp. 2016

Other information

Language

English

Type of outcome

Stať ve sborníku

Field of Study

10403 Physical chemistry

Country of publisher

Netherlands

Confidentiality degree

není předmětem státního či obchodního tajemství

Publication form

electronic version available online

Organization unit

Faculty of Science

Keywords (in Czech)

eliminační voltametrie; rtuťová elektroda; pevné elektrody;rychlost polarizace; potenciálový posun

Keywords in English

elimination voltammetry; mercury electrode; solid electrodes; scan rate; potential shift

Tags

Změněno: 17/5/2018 14:08, Ing. Nicole Zrilić

Abstract

V originále

The theory of elimination voltammetry with linear scan (EVLS) was published and experimentally verified for reversible, quasi-reversible and irreversible electrode systems [1,2]. To date, this method has found application not only in electroanalysis but also in the study of electroactive inorganic and organic substances on mercury, silver, or graphite electrodes [3-5]. The discussed elimination procedure can be considered a mathematical model of the transformation of current-potential curves; the model eliminates some current components while conserving others. The elimination of chosen particular currents is provided by elimination function defining a linear combination of total currents measured at different scan rates. One total current is chosen as a reference current and the corresponding scan rate is called reference scan rate, vref. For an adsorbed electroactive substance, the function that eliminates the charging and kinetic current components and conserves the diffusion current component yields a specific, sensitive, and well-developed peak-counterpeak (p-cp) signal [6-8]. The paper presents the EVLS transformation of irreversible current-potential curves where irreversible currents can be expressed in the general form Iir = vxY{E+αln(v/vref)}, where the function Y is independent of scan rate v. Then, the EVLS function eliminating the diffusion and charging currents will be transformed for irreversible currents as follows: f(I) = 6.8284I1/2(E-ΔE) – 8.2426I(E) + 2.4142I2(E+ΔE) where we have, for the potential shift, ΔE = (RT/αnF) ln2. Because the αn value is a priori unknown, the potential shift value shall be determined experimentally. Within this context, the shift enables us to determine the αn value, which defines the slowest steps of the investigated electrode process. Importantly, in the general sense, the expanded voltammetry procedure provides the determination of the αn term, which is an operation not commonly achievable with standard electrochemical techniques. Moreover, the experimental verification of theoretical results indicates a significant opportunity for the expansion of an electrode potential range (potential window).

Links

LD15058, research and development project
Name: Příprava substrátů pro povrchově zesílenou Ramanovu spektroskopii pomocí elektrochemických, elektroforetických a jiskrový výboj využívajících technik. (Acronym: ELE-SERS)
Investor: Ministry of Education, Youth and Sports of the CR