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).
| Identifer | oai:union.ndltd.org:Rhodes/oai:eprints.ru.ac.za:474 |
| Date | 08 1900 |
| Creators | Ozoemena, K.I., Pillay, J., Nyokong, T. |
| Source Sets | Rhodes University SA |
| Detected Language | English |
| Type | Article, PeerReviewed |
| Format | application/pdf |
| Relation | http://dx.doi.org/10.1016/j.elecom.2006.05.031, http://eprints.ru.ac.za/474/ |
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