Parameters of n-hexanol adsorption on Au (111). Comparison between differential capacity and chronocoulometry results

• Type: Article in International Scientific Journal
• Date: 1999

Authors

Sottomayor, MJ (Author) FCUP; Coelho, V (Author) Other; Ferreira, AP (Author) Other; Silva, F (Author) FCUP; Baturina, OA (Author) Other; Safonov, VA (Author) Other; Damaskin, BB (Author) Other

Journal

Title: Electrochimica Acta

Vol. 45

Pages: 775-787

ISSN: 0013-4686

Publisher: Elsevier

Indexing

ISI Web of Knowledge - 10 Citations

Scopus - 9 Citations

Scientific classification

FOS: Natural sciences > Chemical sciences

Other information

Authenticus ID: P-001-5JJ

DOI: 10.1016/s0013-4686(99)00256-x

Abstract (EN): The adsorption behaviour of n-hexanol on a Au (111) single-crystal electrode from aqueous 0.2 mol dm(-3) NaClO4 was studied on the basis of dynamic capacity measurements and of capacitive charge measurements by chronocoulometry. The charge density, sigma(M), as a function of the applied potential, E, and of the n-hexanol concentration was analysed thermodynamically, yielding the Gibbs surface excess, Gamma, and the Gibbs energy of adsorption, Delta(ads)G degrees, of n-hexanol as a function of potential and concentration. The results of the thermodynamic analysis of the adsorption data at the potential of maximum adsorption are discussed in comparison with the literature data for the adsorption of this compound on Hg [1,2] and on silver single-crystals [3,4]. The results obtained show that the adsorption process could be described by a Frumkin isotherm, the parameters of which were determined and discussed. The values of the standard Gibbs energy of adsorption suggest physical adsorption of the alcohol, without the existence of specific interactions of the adsorbed molecules with gold. Differences and inconsistencies for the results obtained from the analysis of charge and capacity data are discussed in terms of the experimental technique.

Language: English

Type (Professor's evaluation): Scientific

No. of pages: 13