Influence of conductive porous electrodes on the apparent electrode kinetics of fenitrothion

Jangid, K., Gupta, R. , Sahu, R. P., Zhitomirsky, I. and Puri, I. K. (2022) Influence of conductive porous electrodes on the apparent electrode kinetics of fenitrothion. Journal of Electroanalytical Chemistry, 910, 116200. (doi: 10.1016/j.jelechem.2022.116200)

Abstract

Planar bare electrodes fabricated with surface-modified multiwalled carbon nanotubes (MWCNT) are used to detect organophosphate (OP) compounds, which are used as herbicides and fungicides but are harmful to human health. Deposition of carbon nanotubes on the surfaces of bare electrodes enhances electrocatalysis, increasing the electrode to analyte current response and narrowing peak-to-peak potential separation during cyclic voltammetry (CV). We hypothesize that, as the thickness of the deposited MWCNT layer decreases, Fenitrothion (FT, an OP) mass transport between the layers of porous multiwalled carbon nanotubes changes from semi-infinite to thin-layer diffusion. This influences the electrode electrochemical response to the analyte. Using simulations and experiments, we show that when porous MWCNT are deposited on a conductive glassy carbon electrode the mass transport of FT changes from semi-infinite to thin-layer diffusion during CV. This alters the electrochemical response of the electrode and reduces peak-to-peak potential separation. To simulate CV response to multi-step and multi-electron electrochemical reactions of FT, both the semi-infinite and thin-layer diffusion models are employed for the planar bare and modified porous surface electrodes. The transition from thin layer to semi-infinite diffusion is clear when the nanotube layer thickness on the bare electrode increases. The model is applicable to other toxic chemicals, such as 4-nitrophenol, parathion, or methyl parathion that have similar electrode kinetics.

• Item Type: Articles
• Additional Information: This work was supported by the Natural Sciences and Engineering Research Council of Canada (NSERC) Discovery Grant (RGPIN-2019-06571).
• Status: Published
• Refereed: Yes
• Glasgow Author(s) Enlighten ID: Gupta, Dr Rohit
• Authors: Jangid, K., Gupta, R., Sahu, R. P., Zhitomirsky, I., and Puri, I. K.
• College/School: College of Science and Engineering > School of Engineering > Systems Power and Energy
• Journal Name: Journal of Electroanalytical Chemistry
• Publisher: Elsevier
• ISSN: 1572-6657
• ISSN (Online): 1873-2569
• Published Online: 04 March 2022
• Copyright Holders: Copyright © 2022 Elsevier B.V
• First Published: First published in Journal of Electroanalytical Chemistry 910:116200
• Publisher Policy: Reproduced in accordance with the publisher copyright policy