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Detection of hydroxide ions in aqueous solutions by steady-state voltammetry

Detection of hydroxide ions in aqueous solutions by steady-state voltammetry
Detection of hydroxide ions in aqueous solutions by steady-state voltammetry
The electrochemical oxidation of hydroxide ions on microdisk electrodes was studied to find the conditions where the steady-state current can be used for analytical applications. Results are presented for the dependence of the voltammetric response on the microdisk radius, the electrode material and the hydroxide concentration. Well-defined waves for hydroxide oxidation were obtained under steady-state conditions with all microdisks employed. However, the steady-state wave splits for some hydroxide concentrations and radii, but the overall current is still proportional to the concentration. The usefulness of the wave for analytical applications depends on the electrode material. Although the wave is seen on nickel, platinum and gold the latter is the most promising for the amperometric detection of basicity of aqueous solutions. On platinum, the wave can be used but the plateau is not so well defined. On nickel, oxide formation makes measurements difficult. Under steady-state conditions a well-defined wave attributed to the direct oxidation of hydroxide ions was also observed on a gold rotating disk electrode. The wave height was found to be proportional to the square root of the rotation speed, thus indicating that the process was under diffusion control. The limiting current was also found to be proportional to the concentration of hydroxide ions over the range 0.05-10 mM.
hydroxide oxidation, microelectrode, voltammetry, scanning electrochemical microscopy, supporting electrolyte, weakacids, hydrogen evolution, polyprotic acids, reduction, microelectrodes, gold
1040-0397
289-294
Abdelsalam, Mamdouh Elsayed
d1cbddcb-9f5c-46d5-b774-1bbaee26e115
Denuault, Guy
5c76e69f-e04e-4be5-83c5-e729887ffd4e
Baldo, M. Antonietta
dc81685a-3ceb-4ca5-b767-db7587ec8b5b
Bragato, Carlo
78869737-4e49-4eee-8725-28001ff0e202
Daniele, Salvatore
cd677266-5cc2-48c2-8145-e95861a0b4d2
Abdelsalam, Mamdouh Elsayed
d1cbddcb-9f5c-46d5-b774-1bbaee26e115
Denuault, Guy
5c76e69f-e04e-4be5-83c5-e729887ffd4e
Baldo, M. Antonietta
dc81685a-3ceb-4ca5-b767-db7587ec8b5b
Bragato, Carlo
78869737-4e49-4eee-8725-28001ff0e202
Daniele, Salvatore
cd677266-5cc2-48c2-8145-e95861a0b4d2

Abdelsalam, Mamdouh Elsayed, Denuault, Guy, Baldo, M. Antonietta, Bragato, Carlo and Daniele, Salvatore (2001) Detection of hydroxide ions in aqueous solutions by steady-state voltammetry. Electroanalysis, 13 (4), 289-294. (doi:10.1002/1521-4109(200103)13:4<289::AID-ELAN289>3.0.CO;2-F).

Record type: Article

Abstract

The electrochemical oxidation of hydroxide ions on microdisk electrodes was studied to find the conditions where the steady-state current can be used for analytical applications. Results are presented for the dependence of the voltammetric response on the microdisk radius, the electrode material and the hydroxide concentration. Well-defined waves for hydroxide oxidation were obtained under steady-state conditions with all microdisks employed. However, the steady-state wave splits for some hydroxide concentrations and radii, but the overall current is still proportional to the concentration. The usefulness of the wave for analytical applications depends on the electrode material. Although the wave is seen on nickel, platinum and gold the latter is the most promising for the amperometric detection of basicity of aqueous solutions. On platinum, the wave can be used but the plateau is not so well defined. On nickel, oxide formation makes measurements difficult. Under steady-state conditions a well-defined wave attributed to the direct oxidation of hydroxide ions was also observed on a gold rotating disk electrode. The wave height was found to be proportional to the square root of the rotation speed, thus indicating that the process was under diffusion control. The limiting current was also found to be proportional to the concentration of hydroxide ions over the range 0.05-10 mM.

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More information

Published date: 2001
Keywords: hydroxide oxidation, microelectrode, voltammetry, scanning electrochemical microscopy, supporting electrolyte, weakacids, hydrogen evolution, polyprotic acids, reduction, microelectrodes, gold

Identifiers

Local EPrints ID: 19371
URI: https://eprints.soton.ac.uk/id/eprint/19371
ISSN: 1040-0397
PURE UUID: 189f4fd8-c46e-4143-86a1-580fdd9b4a85
ORCID for Guy Denuault: ORCID iD orcid.org/0000-0002-8630-9492

Catalogue record

Date deposited: 13 Feb 2006
Last modified: 17 Oct 2018 00:36

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Contributors

Author: Mamdouh Elsayed Abdelsalam
Author: Guy Denuault ORCID iD
Author: M. Antonietta Baldo
Author: Carlo Bragato
Author: Salvatore Daniele

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