In situ ESR and UV/vis spectroelectrochemical study of eosin Y upon reduction with and without Zn(II) ions.
The electroreduction of eosin Y on a platinum electrode in deaerated slightly acidic aqueous 0.1 mol L(-1) potassium chloride medium is followed in situ by electron spin resonance (ESR) spectroscopy and UV/Vis spectroscopy. The electrochemical formation of a semiquinone radical is proved by both the appearance of an absorbing band at 408 nm, and a strong ESR signal observed during a negative-going scan. The system is also studied in the presence of Zn(II) ions due to its importance for understanding the growth mechanism of nanostructured ZnO/Eosin Y hybrid films by electrodeposition; under such conditions the ESR and UV/Vis response of the semiquinone radical is not observed. Zinc (II) ions form a complex with the dye, which is reduced by a fast two-electron process.
Goux
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Abteilung Elektrochemie und Leitfähige Polymere, Leibniz-Institut für Festkörper- und Werkstoffforschung Dresden, Helmholtzstrasse 20, 01069 Dresden, Germany.
Pauporté
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T
Lincot
D
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Dunsch
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