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Titolo:
Electro-oxidation of 2-mercaptoethanol on adsorbed monomeric and electropolymerized cobalt tetra-aminophthalocyanine films. Effect of film thickness
Autore:
Griveau, S; Pavez, J; Zagal, JH; Bedioui, F;
Indirizzi:
Ecole Natl Super Chim Paris, UMR CNRS, Lab Electrochim & Chim Analyt, ENSCP 7575, F-75231 Paris 05, France Ecole Natl Super Chim Paris Paris France05 75, F-75231 Paris 05, France Univ Santiago Chile, Fac Quim & Biol, Dept Quim Mat, Santiago, Chile Univ Santiago Chile Santiago Chile Biol, Dept Quim Mat, Santiago, Chile
Titolo Testata:
JOURNAL OF ELECTROANALYTICAL CHEMISTRY
fascicolo: 1-2, volume: 497, anno: 2001,
pagine: 75 - 83
Fonte:
ISI
Lingua:
ENG
Soggetto:
CATALYTIC ELECTROOXIDATION; DIOXYGEN REDUCTION; METALLOPHTHALOCYANINES; ELECTROCATALYSIS; GRAPHITE; REDOX;
Keywords:
monomeric cobalt-tetraaminophthalocyanine; polymerized cobalt-tetraaminophthalocyanine; thiol oxidation; film thickness; electrocatalytic activity;
Tipo documento:
Article
Natura:
Periodico
Settore Disciplinare:
Physical, Chemical & Earth Sciences
Citazioni:
19
Recensione:
Indirizzi per estratti:
Indirizzo: Bedioui, F Ecole Natl Super Chim Paris, UMR CNRS, Lab Electrochim & Chim Analyt, ENSCP 7575, 11 Rue Pierre & Marie Curie, F-75231 Paris 05, France Ecole Natl Super Chim Paris 11 Rue Pierre & Marie Curie Paris France 05
Citazione:
S. Griveau et al., "Electro-oxidation of 2-mercaptoethanol on adsorbed monomeric and electropolymerized cobalt tetra-aminophthalocyanine films. Effect of film thickness", J ELEC CHEM, 497(1-2), 2001, pp. 75-83

Abstract

We have investigated the electrocatalytic activity of cobalt tetra-aminophthalocyanine (CoTAPc) for the one-electron oxidation of 2-mercaptoethanol (2-ME) using adsorbed monomeric CoTAPc and electropolymerized poly-CoTAPc films of different thickness on Vitreous carbon electrode. Our results show that the activity of poly-CoTAPc increases slightly with the thickness of the film, while the activity of the adsorbed monomeric CoTAPc is still greatest. The trend in activities, analysed by cyclic voltammetry, is the same for the electro-oxidation of 2-ME and for the electroreduction of the corresponding disulphide. Tafel plots obtained from rotating disk measurement for adsorbed CoTAPc and poly-CoTAPc film modified electrodes show slopes close to RT/F (ca. 70 mV) at low polarisation potentials which increase graduallywith potential to values close to 2RT/F (120 mV). This suggests that at low polarisation the rate-determining step is a chemical step (formation of ametal complex-thiol adduct) preceded by a fast electron-transfer step involving the CoTAPc. At higher polarisations the one electron oxidation of theadduct to give the thiyl radical becomes rate controlling. Even though monomeric CoTAPc adsorbed on glassy carbon presents higher activity for the electro-oxidation of 2-ME, the high stability of the electropolymerized poly-CoTAPc makes them more attractive for applications in the activation and/orthe amperometric detection of thiols. (C) 2001 Elsevier Science B.V. All rights reserved.

ASDD Area Sistemi Dipartimentali e Documentali, Università di Bologna, Catalogo delle riviste ed altri periodici
Documento generato il 23/09/20 alle ore 13:09:44