dc.contributor.author |
Nkosi, D
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dc.contributor.author |
Pillay, J
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dc.contributor.author |
Ozoemena, KI
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dc.contributor.author |
Nouneh, K
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dc.contributor.author |
Oyama, M
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dc.date.accessioned |
2011-03-30T08:49:56Z |
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dc.date.available |
2011-03-30T08:49:56Z |
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dc.date.issued |
2010-01 |
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dc.identifier.citation |
Nkosi, D, Pillay, J, Ozoemena, KI et al. 2010. Heterogeneous electron transfer kinetics and electrocatalytic behaviour of mixed self-assembled ferrocenes and SWCNT layers. Physical Chemistry Chemical Physics, Vol. 129(3), pp 604-613 |
en_US |
dc.identifier.issn |
1463-9076 |
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dc.identifier.uri |
http://www.ncbi.nlm.nih.gov/pubmed/20066346
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dc.identifier.uri |
http://hdl.handle.net/10204/4935
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dc.description |
Copyright: 2010 the Owner Societies |
en_US |
dc.description.abstract |
The electron transfer dynamics and electrocatalytic behaviour of ferrocene-terminated self-assembled monolayers (SAMs), co-adsorbed with single-walled carbon nanotubes (SWCNTs) on a gold electrode, have been interrogated for the first time. Ferrocene monocarboxylic acid (FMCA) or ferrocene dicarboxylic acid (FDCA) was covalently attached to the cysteamine (Cys) monolayer to form Au-Cys-FMCA and Au-Cys-FDCA, respectively. The same covalent attachment strategy was used to form the mixed SWCNTs and ferrocene-terminated layers (i.e. Au-Cys-SWCNT/FMCA and Au-Cys-SWCNT/FDCA). Using cyclic voltammetry and electrochemical impedance spectroscopy, the impact of neighbouring SWCNTs on the electron transfer dynamics of the ferrocene molecular assemblies in an acidic medium (0.5 M H(2)SO(4)) and in a solution of an outer-sphere redox probe ([Fe(CN)(6)](4-)/[Fe(CN)(6)](3-)) was explored. The electron transfer rate constants in both media essentially decreased as Au-Cys-FMCA > Au-Cys-SWCNT/FDCA > Au-Cys-FDCA > Au-Cys-SWCNT/FMCA. This trend has been interpreted in terms of several factors such as the locations of the ferrocene species in a range of environments with a range of potentials, the proximity/interactions of the ferrocenes with one another, and electrostatic interaction or repulsion existing between the negatively-charged redox probe and the modified electrodes. The thiocyanate ion (SCN(-)) was used as a model analyte to examine the influence of the neighbouring SWCNTs on the electrocatalytic ability of the ferrocene assemblies. The Au-Cys-SWCNT/FDCA showed the best catalytic activity (in terms of onset potential and catalytic peak current height) for the oxidation of SCN(-), possibly due to the repulsive interactions between the negatively charged SCN(-) and high number of surface -COOH species at the SWCNT/FDCA. This study has provided some useful insights as to how CNTs co-assembled with ferrocene-terminated thiols could impact on the electron transfer kinetics as well as the electrocatalytic detection of the self-assembled ferrocene layers. |
en_US |
dc.language.iso |
en |
en_US |
dc.publisher |
The Royal Society of Chemistry |
en_US |
dc.relation.ispartofseries |
Workflow request;6125 |
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dc.subject |
Transfer kinetics |
en_US |
dc.subject |
Kinetics |
en_US |
dc.subject |
Electron transfer kinetics |
en_US |
dc.subject |
Self-assembled monolayers |
en_US |
dc.subject |
Single walled carbon nanotubes |
en_US |
dc.subject |
Electrocatalytic behaviour |
en_US |
dc.subject |
Electrocatalysis |
en_US |
dc.subject |
Self-assembled ferrocenes |
en_US |
dc.subject |
Chemistry chemical |
en_US |
dc.subject |
Chemistry chemical physics, |
en_US |
dc.title |
Heterogeneous electron transfer kinetics and electrocatalytic behaviour of mixed self-assembled ferrocenes and SWCNT layers |
en_US |
dc.type |
Article |
en_US |
dc.identifier.apacitation |
Nkosi, D., Pillay, J., Ozoemena, K., Nouneh, K., & Oyama, M. (2010). Heterogeneous electron transfer kinetics and electrocatalytic behaviour of mixed self-assembled ferrocenes and SWCNT layers. http://hdl.handle.net/10204/4935 |
en_ZA |
dc.identifier.chicagocitation |
Nkosi, D, J Pillay, KI Ozoemena, K Nouneh, and M Oyama "Heterogeneous electron transfer kinetics and electrocatalytic behaviour of mixed self-assembled ferrocenes and SWCNT layers." (2010) http://hdl.handle.net/10204/4935 |
en_ZA |
dc.identifier.vancouvercitation |
Nkosi D, Pillay J, Ozoemena K, Nouneh K, Oyama M. Heterogeneous electron transfer kinetics and electrocatalytic behaviour of mixed self-assembled ferrocenes and SWCNT layers. 2010; http://hdl.handle.net/10204/4935. |
en_ZA |
dc.identifier.ris |
TY - Article
AU - Nkosi, D
AU - Pillay, J
AU - Ozoemena, KI
AU - Nouneh, K
AU - Oyama, M
AB - The electron transfer dynamics and electrocatalytic behaviour of ferrocene-terminated self-assembled monolayers (SAMs), co-adsorbed with single-walled carbon nanotubes (SWCNTs) on a gold electrode, have been interrogated for the first time. Ferrocene monocarboxylic acid (FMCA) or ferrocene dicarboxylic acid (FDCA) was covalently attached to the cysteamine (Cys) monolayer to form Au-Cys-FMCA and Au-Cys-FDCA, respectively. The same covalent attachment strategy was used to form the mixed SWCNTs and ferrocene-terminated layers (i.e. Au-Cys-SWCNT/FMCA and Au-Cys-SWCNT/FDCA). Using cyclic voltammetry and electrochemical impedance spectroscopy, the impact of neighbouring SWCNTs on the electron transfer dynamics of the ferrocene molecular assemblies in an acidic medium (0.5 M H(2)SO(4)) and in a solution of an outer-sphere redox probe ([Fe(CN)(6)](4-)/[Fe(CN)(6)](3-)) was explored. The electron transfer rate constants in both media essentially decreased as Au-Cys-FMCA > Au-Cys-SWCNT/FDCA > Au-Cys-FDCA > Au-Cys-SWCNT/FMCA. This trend has been interpreted in terms of several factors such as the locations of the ferrocene species in a range of environments with a range of potentials, the proximity/interactions of the ferrocenes with one another, and electrostatic interaction or repulsion existing between the negatively-charged redox probe and the modified electrodes. The thiocyanate ion (SCN(-)) was used as a model analyte to examine the influence of the neighbouring SWCNTs on the electrocatalytic ability of the ferrocene assemblies. The Au-Cys-SWCNT/FDCA showed the best catalytic activity (in terms of onset potential and catalytic peak current height) for the oxidation of SCN(-), possibly due to the repulsive interactions between the negatively charged SCN(-) and high number of surface -COOH species at the SWCNT/FDCA. This study has provided some useful insights as to how CNTs co-assembled with ferrocene-terminated thiols could impact on the electron transfer kinetics as well as the electrocatalytic detection of the self-assembled ferrocene layers.
DA - 2010-01
DB - ResearchSpace
DP - CSIR
KW - Transfer kinetics
KW - Kinetics
KW - Electron transfer kinetics
KW - Self-assembled monolayers
KW - Single walled carbon nanotubes
KW - Electrocatalytic behaviour
KW - Electrocatalysis
KW - Self-assembled ferrocenes
KW - Chemistry chemical
KW - Chemistry chemical physics,
LK - https://researchspace.csir.co.za
PY - 2010
SM - 1463-9076
T1 - Heterogeneous electron transfer kinetics and electrocatalytic behaviour of mixed self-assembled ferrocenes and SWCNT layers
TI - Heterogeneous electron transfer kinetics and electrocatalytic behaviour of mixed self-assembled ferrocenes and SWCNT layers
UR - http://hdl.handle.net/10204/4935
ER -
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en_ZA |