The methyl viologen incorporated zeolite modified carbon paste electrode—part 1. Electrochemical behaviour in aqueous media. Effects of supporting electrolyte and immersion time
✍ Scribed by A. Walcarius; L. Lamberts; E.G. Derouane
- Publisher
- Elsevier Science
- Year
- 1993
- Tongue
- English
- Weight
- 885 KB
- Volume
- 38
- Category
- Article
- ISSN
- 0013-4686
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✦ Synopsis
Abstrad-Methyl viologen (MV++) is incorporated into a xeolite modified carbon paste electrode (ZMCPE). The electrochemical behaviour of MV++ is examined in aqueous medii with various supporting electrolytes (NaCl, NaBr and several tetraalkylammonium bromides) by cyclic VoltammeWy, chronoamperometry and chronocoulometry. Quantitative in situ determination of MV+ + leaching from paste into the external solution is performed using square wave voltammetry. The thickness of the ZMCPE involved in the electrochemical reaction of MV+ + has been found to increase with experiment time. This was not the case with unmodified carbon paste. The diffusion coeiTicient of free MV + + within a ZMCPE is calculated to be about 8 x lo-"cm*s-'.
This value increases (3 x 10-'"cm's-') when the paste is equilibrated in high purity water for several hours before being used to obtain the "hydrated" form of a ZMCPE.