MECHANISTIC STUDIES OF THE PHOTODISSOCIATION OF PHYSISORBED O-2/GRAPHITE
We have investigated the vacuum ultra-violet photodissociation of molecular O2 physisorbed on graphite using synchrotron radiation with photon energies in the range 13-35 eV. The yield of desorbed O+ ions shows a threshold at nearly 19.5 eV and resonances at 24.5 eV and 28.5 eV, contrasting strongly...
| Main Authors: | , , , , , , |
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| Format: | Journal article |
| Language: | English |
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1994
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| _version_ | 1826258269248684032 |
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| author | Bennett, R Bennett, S Siller, L Macdonald, M Palmer, R Wright, H Foord, J |
| author_facet | Bennett, R Bennett, S Siller, L Macdonald, M Palmer, R Wright, H Foord, J |
| author_sort | Bennett, R |
| collection | OXFORD |
| description | We have investigated the vacuum ultra-violet photodissociation of molecular O2 physisorbed on graphite using synchrotron radiation with photon energies in the range 13-35 eV. The yield of desorbed O+ ions shows a threshold at nearly 19.5 eV and resonances at 24.5 eV and 28.5 eV, contrasting strongly with the gas phase photodissociation cross section. the principal mechanism of O+ production appears to be dipolar dissociation drive by photoelectrons generated in the substrate. An enchancement in the detection efficiency of low-energy ions, compared with previous measurements, has identified an additional dissociation mechanism leading to the desorption of O- ions. Specifically, the results support a channel for low-energy O- desorption, attributed to the dissociative attachment of photoelectrons, again generated in the graphite substrate, to the physisorbed O2 molecules. |
| first_indexed | 2024-03-06T18:31:17Z |
| format | Journal article |
| id | oxford-uuid:09bdc33b-8ad9-4f88-930f-b35093e1a6e9 |
| institution | University of Oxford |
| language | English |
| last_indexed | 2024-03-06T18:31:17Z |
| publishDate | 1994 |
| record_format | dspace |
| spelling | oxford-uuid:09bdc33b-8ad9-4f88-930f-b35093e1a6e92022-03-26T09:19:55ZMECHANISTIC STUDIES OF THE PHOTODISSOCIATION OF PHYSISORBED O-2/GRAPHITEJournal articlehttp://purl.org/coar/resource_type/c_dcae04bcuuid:09bdc33b-8ad9-4f88-930f-b35093e1a6e9EnglishSymplectic Elements at Oxford1994Bennett, RBennett, SSiller, LMacdonald, MPalmer, RWright, HFoord, JWe have investigated the vacuum ultra-violet photodissociation of molecular O2 physisorbed on graphite using synchrotron radiation with photon energies in the range 13-35 eV. The yield of desorbed O+ ions shows a threshold at nearly 19.5 eV and resonances at 24.5 eV and 28.5 eV, contrasting strongly with the gas phase photodissociation cross section. the principal mechanism of O+ production appears to be dipolar dissociation drive by photoelectrons generated in the substrate. An enchancement in the detection efficiency of low-energy ions, compared with previous measurements, has identified an additional dissociation mechanism leading to the desorption of O- ions. Specifically, the results support a channel for low-energy O- desorption, attributed to the dissociative attachment of photoelectrons, again generated in the graphite substrate, to the physisorbed O2 molecules. |
| spellingShingle | Bennett, R Bennett, S Siller, L Macdonald, M Palmer, R Wright, H Foord, J MECHANISTIC STUDIES OF THE PHOTODISSOCIATION OF PHYSISORBED O-2/GRAPHITE |
| title | MECHANISTIC STUDIES OF THE PHOTODISSOCIATION OF PHYSISORBED O-2/GRAPHITE |
| title_full | MECHANISTIC STUDIES OF THE PHOTODISSOCIATION OF PHYSISORBED O-2/GRAPHITE |
| title_fullStr | MECHANISTIC STUDIES OF THE PHOTODISSOCIATION OF PHYSISORBED O-2/GRAPHITE |
| title_full_unstemmed | MECHANISTIC STUDIES OF THE PHOTODISSOCIATION OF PHYSISORBED O-2/GRAPHITE |
| title_short | MECHANISTIC STUDIES OF THE PHOTODISSOCIATION OF PHYSISORBED O-2/GRAPHITE |
| title_sort | mechanistic studies of the photodissociation of physisorbed o 2 graphite |
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