The electrocatalytic properties of Arc-MWCNTs and associated 'Carbon Onions'
For the first time we report on the electrochemical characteristics of nanometer sized polyhedral graphite onions dispersed amongst arc-MWCNTs. These are formed during the electric arc discharge method of producing ultrapure MWCNTs (arc-MWCNTs). The carbon onions are randomly dispersed amongst the a...
| Main Authors: | , , , , , |
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| Format: | Journal article |
| Language: | English |
| Published: |
2008
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| _version_ | 1797062403953786880 |
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| author | Henstridge, M Shao, L Wildgoose, G Compton, R Tobias, G Green, M |
| author_facet | Henstridge, M Shao, L Wildgoose, G Compton, R Tobias, G Green, M |
| author_sort | Henstridge, M |
| collection | OXFORD |
| description | For the first time we report on the electrochemical characteristics of nanometer sized polyhedral graphite onions dispersed amongst arc-MWCNTs. These are formed during the electric arc discharge method of producing ultrapure MWCNTs (arc-MWCNTs). The carbon onions are randomly dispersed amongst the arc-MWCNTs which are produced with very little amorphous carbon deposits or other unwanted impurities and are formed as closed-ended tubes. By comparison with commercially available open-ended hollow-tube multiwalled carbon nanotubes made using the chemical vapor deposition method (cvd-MWCNTs), a glassy carbon electrode (GCE), an edge-plane pyrolytic graphite electrode (eppg) and basal plane pyrolytic graphite (bppg) electrode, we can speculate that it is the edge-plane-like defect sites that are the electroactive sites responsible for the apparent 'electrocatalysis' seen with a wide range of analytes including: ferrocyanide, ruthenium hexaamine(III), nicotinamide adenosine dinucleotide (NADH), epinephrine, norepinephrine, cysteine, and glutathione. The arc-MWCNTs themselves are produced as closed-ended tubes with very few, if any, edge-plane-like defect sites evident in their HRTEM characterization. Therefore we speculate that it is the carbon onions dispersed amongst the arc-MWCNTs which have incomplete graphite shells or a rolled-up 'Swiss-roll' structures that posses the edge-plane-like defect sites and are responsible for the observed voltammetric responses. Carbon onions are no more or no less 'electrocatalytic' than open-ended MWCNTs which in turn are no more electrocatalytic than an eppg electrode. As the carbon onions are ubiquitous in MWCNTs formed using the arc-discharge method the authors advise that caution should be taken before assigning any electrocatalytic behavior to the MWCNTs themselves as any observed electrocatalysis likely arises from the carbon onion impurities. © 2008 Wiley-VCH Verlag GmbH and Co. KGaA. |
| first_indexed | 2024-03-06T20:45:03Z |
| format | Journal article |
| id | oxford-uuid:359ab61f-04d5-460d-8c83-f36ae3ef2c55 |
| institution | University of Oxford |
| language | English |
| last_indexed | 2024-03-06T20:45:03Z |
| publishDate | 2008 |
| record_format | dspace |
| spelling | oxford-uuid:359ab61f-04d5-460d-8c83-f36ae3ef2c552022-03-26T13:32:55ZThe electrocatalytic properties of Arc-MWCNTs and associated 'Carbon Onions'Journal articlehttp://purl.org/coar/resource_type/c_dcae04bcuuid:359ab61f-04d5-460d-8c83-f36ae3ef2c55EnglishSymplectic Elements at Oxford2008Henstridge, MShao, LWildgoose, GCompton, RTobias, GGreen, MFor the first time we report on the electrochemical characteristics of nanometer sized polyhedral graphite onions dispersed amongst arc-MWCNTs. These are formed during the electric arc discharge method of producing ultrapure MWCNTs (arc-MWCNTs). The carbon onions are randomly dispersed amongst the arc-MWCNTs which are produced with very little amorphous carbon deposits or other unwanted impurities and are formed as closed-ended tubes. By comparison with commercially available open-ended hollow-tube multiwalled carbon nanotubes made using the chemical vapor deposition method (cvd-MWCNTs), a glassy carbon electrode (GCE), an edge-plane pyrolytic graphite electrode (eppg) and basal plane pyrolytic graphite (bppg) electrode, we can speculate that it is the edge-plane-like defect sites that are the electroactive sites responsible for the apparent 'electrocatalysis' seen with a wide range of analytes including: ferrocyanide, ruthenium hexaamine(III), nicotinamide adenosine dinucleotide (NADH), epinephrine, norepinephrine, cysteine, and glutathione. The arc-MWCNTs themselves are produced as closed-ended tubes with very few, if any, edge-plane-like defect sites evident in their HRTEM characterization. Therefore we speculate that it is the carbon onions dispersed amongst the arc-MWCNTs which have incomplete graphite shells or a rolled-up 'Swiss-roll' structures that posses the edge-plane-like defect sites and are responsible for the observed voltammetric responses. Carbon onions are no more or no less 'electrocatalytic' than open-ended MWCNTs which in turn are no more electrocatalytic than an eppg electrode. As the carbon onions are ubiquitous in MWCNTs formed using the arc-discharge method the authors advise that caution should be taken before assigning any electrocatalytic behavior to the MWCNTs themselves as any observed electrocatalysis likely arises from the carbon onion impurities. © 2008 Wiley-VCH Verlag GmbH and Co. KGaA. |
| spellingShingle | Henstridge, M Shao, L Wildgoose, G Compton, R Tobias, G Green, M The electrocatalytic properties of Arc-MWCNTs and associated 'Carbon Onions' |
| title | The electrocatalytic properties of Arc-MWCNTs and associated 'Carbon Onions' |
| title_full | The electrocatalytic properties of Arc-MWCNTs and associated 'Carbon Onions' |
| title_fullStr | The electrocatalytic properties of Arc-MWCNTs and associated 'Carbon Onions' |
| title_full_unstemmed | The electrocatalytic properties of Arc-MWCNTs and associated 'Carbon Onions' |
| title_short | The electrocatalytic properties of Arc-MWCNTs and associated 'Carbon Onions' |
| title_sort | electrocatalytic properties of arc mwcnts and associated carbon onions |
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