Pencil graphite electrodes for in-situ spectroelectrochemical sensing of reaction intermediates and products in organic solvents

0582989 - ÚFCH JH 2025 RIV NL eng J - Journal Article
Vaněčková, Eva - Hrdlička, Vojtěch - Šebera, Jakub - Hromadová, Magdaléna - Kocábová, Jana - Sebechlebská, Táňa - Kolivoška, Viliam
Pencil graphite electrodes for in-situ spectroelectrochemical sensing of reaction intermediates and products in organic solvents.
Analytica Chimica Acta. Roč. 1296, APR 2024 (2024), č. článku 342350. ISSN 0003-2670. E-ISSN 1873-4324
R&D Projects: GA ČR(CZ) GA21-13458S; GA ČR(CZ) GA23-07292S
Grant - others:Akademie věd ČR(CZ) L200402251
Institutional support: RVO:61388955
Keywords : spectroelectrochemistry * charge transfer * cyclic voltammetry
OECD category: Electrochemistry (dry cells, batteries, fuel cells, corrosion metals, electrolysis)
Impact factor: 6.2, year: 2022
Method of publishing: Limited access

Background
Spectroelectrochemistry (SEC) is a valuable analytical tool providing insights to reaction mechanisms and the structure of species involved in charge transfer reactions. Most of commercial SEC setups are based on platinum working electrodes where the adsorption of species involved in reactions often complicates their analysis.
Results
In this work, we employ an array of pencil graphite rods as an optically transparent working electrode in a custom-made air-tight thin-layer cell suitable for the SEC analysis performed here in acetonitrile as a representative non-aqueous solvent. The functionality of the device was demonstrated by UV–Vis SEC sensing of charge transfer reactions of ruthenium acetylacetonate, ferrocene and ethylviologen dibromide redox probes performed employing the cyclic voltammetry. The SEC response obtained for all three probes confirmed no adsorption and the absence of oxygen in the cell. Furthermore, we have developed and utilized finite element method numerical simulations considering charge transfer reactions coupled with the diffusional mass transport to model the cyclic voltammetric response and the reaction conversion in the thin-layer SEC cell.
Significance
Our work paves the way for easy-to-assemble customized air-tight adsorption-free SEC devices with the manufacturing costs well below those of commercially available platforms. Developed computational approaches have the predictive power for optimizing reaction conditions and the geometry of the SEC cell.
Permanent Link: https://hdl.handle.net/11104/0351017