Mechanism and Activity of Photocatalytic Oxygen Evolution on Titania Anatase in Aqueous Surroundings.
Due to its high overpotential and low efficiency, the conversion of water to O using solar energy remains a bottleneck for photocatalytic water splitting. Here the microscopic mechanisms of the oxygen evolution reaction (OER) on differently structured anatase surfaces in aqueous surroundings, namely...
| Publicado en: | Journal of the American Chemical Society Vol. 132; no. 37; pp. 13008 - 13016 |
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| Autores principales: | , , , |
| Formato: | Artículo |
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American Chemical Society
9/22/2010
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| Acceso en línea: | Ver este registro en EBSCOhost |
| fields | @attributes: recordID: 1 pdfLink: plink: https://search.ebscohost.com/login.aspx?direct=true&db=hlh&AN=53901892&site=ehost-live header: @attributes: shortDbName: hlh uiTerm: 53901892 longDbName: Humanities International Complete uiTag: AN controlInfo: bkinfo: jinfo: jid: 00027863 ACS jtl: Journal of the American Chemical Society issn: 00027863 maglogo: N pubinfo: dt: 9/22/2010 vid: 132 iid: 37 pid: 997 pub: American Chemical Society artinfo: ui: 53901892 10.1021/ja105340b ppf: 13008 ppct: 8 formats: tig: atl: Mechanism and Activity of Photocatalytic Oxygen Evolution on Titania Anatase in Aqueous Surroundings. aug: au: Ye-Fei Li Zhi-Pan Liu LuLu Liu Weiguo Gao affil: Shanghai Key Laboratory of Molecular Catalysis and Innovative Materials, Department of Chemistry, Key Laboratory for Computational Physical Sciences, Ministry of Education, Fudan University, Shanghai 200433, China School of Mathematical Sciences, Fudan University, Shanghai 200433, China su: Photosynthetic oxygen evolution Titanium dioxide Solar energy Density functionals Intermediates (Chemistry) Photocatalysis sug: subj: Photosynthetic oxygen evolution Titanium dioxide Solar energy Density functionals Intermediates (Chemistry) Photocatalysis ab: Due to its high overpotential and low efficiency, the conversion of water to O using solar energy remains a bottleneck for photocatalytic water splitting. Here the microscopic mechanisms of the oxygen evolution reaction (OER) on differently structured anatase surfaces in aqueous surroundings, namely, (101), (001), and (102), are determined and compared systematically by combining first-principles density functional theory calculations and a parallel periodic continuum solvation model. We show that OER involves the sequential removal of protons from surface oxidative species, forming surface peroxo and superoxo intermediates. The initiating step, the first proton removal, dictates the high overpotential. Only at an overpotential of 0.7 V (1.93 V vs SHE) does this rate-controlling step become surmountable at room temperature: the free energy change of the step is 0.69, 0.63, and 0.61 eV for (101), (102), and (001) surfaces, respectively. We therefore conclude that (I) OER is not sensitive to the local surface structure of anatase and (ii) visible light (<∼590 nm) is, in principle, capable of driving the photocatatlytic OER on anatase kinetically. By co-doping high-valent elements into the anatase subsurface, we demonstrate that the high overpotential of the OER can be significantly reduced, with extra occupied levels above the valence band. pubtype: Academic Journal doctype: Article src: R language: English refInfo: copyright: @attributes: flag: Y dt: @attributes: year: 2010 holdings: @attributes: islocal: N |
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