Preferential electrosorption of cobalt (II) tetra-aminophthalocyanine at single-wall carbon nanotubes immobilized on a basal plane pyrolytic graphite electrode

Ozoemena, K.I. and Pillay, J. and Nyokong, T. (2006) Preferential electrosorption of cobalt (II) tetra-aminophthalocyanine at single-wall carbon nanotubes immobilized on a basal plane pyrolytic graphite electrode. Electrochemistry Communications, 8 (8). pp. 1391-1396. ISSN 1388-2481

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Official URL: http://dx.doi.org/10.1016/j.elecom.2006.05.031

Abstract

This communication describes the preferential electrosorption of cobalt (II) tetra-aminophthalocyanine (CoTAPc) (rather than the expected electropolymerisation) onto a SWCNT immobilized on a basal plane pyrolytic graphite electrode (BPPGE). Cyclic voltammetric and electrochemical impedance spectroscopic data revealed that the electrosorbed CoTAPc is highly stable, well organized with comparable electron-transfer rate constant in ferricyanide solution (k[subscript app] ~ 6 × 10[superscript (−5)] cm s[superscript (−1)] order) to that of the SWNCT. Electrochemical kinetics of the electrosorbed CoTAPc yielded k[subscript s] of 0.169 s[superscript (−1)] and 832.2 s[superscript (−1)] for the cathodic and anodic reactions, respectively, indicative of different rate-determining steps for the cathodic and anodic reactions. Strong π-stacking interactions between CoTAPc and the sidewalls of the SWCNTs, with possible synergistic covalent interactions, are explained as responsible for the preferential electrosorption process. Both BPPGE-SWCNT-CoTAPc[subscript (ads)] and BPPGE-SWCNT showed comparable electrocatalytic responses towards the detection of 2-(diethylamino) ethanethiol (DEAET).

Item Type:Article
Uncontrolled Keywords:Cobalt tetra-aminophthalocyanine; Single-wall carbon nanotube; Basal plane pyrolytic graphite electrode; Electrosorption; DEAET
Subjects:Y Unknown > Subjects to be assigned
Divisions:Faculty > Faculty of Science > Chemistry
ID Code:474
Deposited By: Mrs Eileen Shepherd
Deposited On:30 Nov 2006
Last Modified:06 Jan 2012 16:18
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