A non-conventional way to perform voltammetry

作者：Moscoso R; Inostroza E; Squella J A

来源：Electrochemistry Communications, 2017, 81: 61-64.

DOI：10.1016/j.elecom.2017.06.008

• Non-conventional voltammetry
• Nitrocompounds
• Trapped nitrocompounds electrode
• Thin layer diffusion
• MWCNT

In a conventional voltammetric experiment, the electroactive species is dissolved in solution, and then diffuses from the solution phase to the electrode phase. In our proposed non-conventional voltammetric experiment, the electroactive species is trapped in the electrode phase instead of being dissolved in solution. A non-aqueous solvent was first used to trap the organic species in a porous surface layer and the modified electrode then transferred to an aqueous buffer to conduct voltammetry measurements.
We tested the non-conventional voltammetric mode using a modified multi-walled carbon nanotube electrode containing mono-, di- and tri-nitroaromatic compounds trapped in the porous three-dimensional network of the CNTs. From these experiments, we conclude that the non-conventional mode produces higher peak currents and displacement of the peak potentials, yielding lower overpotentials. Furthermore, it is possible to obtain more selective voltammograms in the non-conventional mode, showing peaks that could not be resolved in the conventional mode.
These results are due to a change in the mass transport regime, with thin layer diffusion being the main transport method in the non-conventional mode, compared to semi-infinite diffusion in the conventional mode.
The proposed approach is an excellent alternative for performing voltammetric studies on insoluble or slightly soluble organic compounds.

• 出版日期2017-8