Potentiodynamic EIS investigation of the 2-methyl-5-mercapto-1,2,4-thiadiazole adsorption on copper

Blajiev, Orlin L; Breugelmans, Tom; Pintelon, Rik; Terryn, Herman; Hubin, Annick

doi:10.1016/J.ELECTACTA.2008.01.048

Title

Potentiodynamic EIS investigation of the 2-methyl-5-mercapto-1,2,4-thiadiazole adsorption on copper

Author

Blajiev, Orlin L

Breugelmans, Tom

Pintelon, Rik

Terryn, Herman

Hubin, Annick

Abstract

The influence of the potential and polarization conditions on the adsorption kinetics and structure of 2-methyl-5-mercapto-1,3,4-thiadiazole on copper was investigated. The study was carried out by means of cyclic voltammetry, differential capacity, and potentiodynamic electrochemical impedance spectroscopy experiments. The total amount of deposited molecules suggested the formation of a dense organic layer. Several possible molecular adsorption geometries were established by considering some relevant quantum-chemical descriptors. Differentiation between them was performed by a derivation of the layer thickness from its capacitance. The latter was obtained by means of differential capacity and potentiodynamic electrochemical impedance spectroscopy measurements. It was shown that the application of potentiodynamic electrochemical impedance spectroscopy instead of differential capacity approach is beneficial in the case of complex or not purely capacitive systems. The results suggested that the polarization rate influenced significantly the morphology of the formed layers.

Language

English

Source (journal)

Electrochimica acta. - London

Publication

London : 2008

ISSN

0013-4686

DOI

10.1016/J.ELECTACTA.2008.01.048

Volume/pages

53 :25 (2008) , p. 7451-7459