Modelling of quantum yields in photocatalytic membrane reactors immobilising titanium dioxide
For some model molecules (methanoic and ethanoic acids, methane, and phenol), systematic investigations of quantum yields were carried out in the present paper, as a function of concentration and of absorbed radiant power. Quantum yields Φ∞, calculated from rates, followed an apparently Langmuirian...
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| Format: | Article |
| Language: | English |
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Wiley
2006-01-01
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| Series: | International Journal of Photoenergy |
| Online Access: | http://dx.doi.org/10.1155/IJP/2006/26870 |
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| author | Ignazio Renato Bellobono Giulia de Martini Paola Maria Tozzi Carmen Canevali Franca Morazzoni Roberto Scotti Riccardo Bianchi |
| author_facet | Ignazio Renato Bellobono Giulia de Martini Paola Maria Tozzi Carmen Canevali Franca Morazzoni Roberto Scotti Riccardo Bianchi |
| author_sort | Ignazio Renato Bellobono |
| collection | DOAJ |
| description | For some model molecules (methanoic and ethanoic acids, methane,
and phenol), systematic investigations of quantum yields were
carried out in the present paper, as a function of concentration
and of absorbed radiant power. Quantum yields Φ∞,
calculated from rates, followed an apparently Langmuirian function
of initial concentration C0, by which Φ∞ values
at “infinite” concentration could be obtained. By having thus
established that quantum yields of photomineralisation
Φ∞ are independent of radiation wavelength, within
the absorption range of semiconductor, but depend on radiant
power, such a dependency was experimentally investigated. For all
the investigated molecules, the maximum allowable values reached
in the low radiant power range clearly appeared as a plateau. On
the contrary, at high radiant power values, another plateau, at a
value of about 1/4-1/5 with respect to the maximum value, was
evident. This was interpreted on the basis of a competition
kinetics of hydroxyl radicals with themselves, leading to hydrogen
peroxide formation, other than with substrate or
intermediate molecules leading to full mineralisation.
Modelling of quantum yields as a function of concentration and
radiant power thus allows a fully consistent and trustworthy
design of photoreactors. |
| format | Article |
| id | doaj-art-10af1454833346009784ad08754be22b |
| institution | Kabale University |
| issn | 1110-662X 1687-529X |
| language | English |
| publishDate | 2006-01-01 |
| publisher | Wiley |
| record_format | Article |
| series | International Journal of Photoenergy |
| spelling | doaj-art-10af1454833346009784ad08754be22b2025-02-03T01:21:21ZengWileyInternational Journal of Photoenergy1110-662X1687-529X2006-01-01200610.1155/IJP/2006/2687026870Modelling of quantum yields in photocatalytic membrane reactors immobilising titanium dioxideIgnazio Renato Bellobono0Giulia de Martini1Paola Maria Tozzi2Carmen Canevali3Franca Morazzoni4Roberto Scotti5Riccardo Bianchi6Environmental Research Centre, University of Milan, Via C. Golgi 19, Milan 20133, ItalyResearch and Development Group, BIT srl, Milan 20121, ItalyResearch and Development Group, BIT srl, Milan 20121, ItalyDepartment of Materials Science, University of Milano Bicocca, Milan 20126, ItalyDepartment of Materials Science, University of Milano Bicocca, Milan 20126, ItalyDepartment of Materials Science, University of Milano Bicocca, Milan 20126, ItalyCNR, ISTM, Milan 20133, ItalyFor some model molecules (methanoic and ethanoic acids, methane, and phenol), systematic investigations of quantum yields were carried out in the present paper, as a function of concentration and of absorbed radiant power. Quantum yields Φ∞, calculated from rates, followed an apparently Langmuirian function of initial concentration C0, by which Φ∞ values at “infinite” concentration could be obtained. By having thus established that quantum yields of photomineralisation Φ∞ are independent of radiation wavelength, within the absorption range of semiconductor, but depend on radiant power, such a dependency was experimentally investigated. For all the investigated molecules, the maximum allowable values reached in the low radiant power range clearly appeared as a plateau. On the contrary, at high radiant power values, another plateau, at a value of about 1/4-1/5 with respect to the maximum value, was evident. This was interpreted on the basis of a competition kinetics of hydroxyl radicals with themselves, leading to hydrogen peroxide formation, other than with substrate or intermediate molecules leading to full mineralisation. Modelling of quantum yields as a function of concentration and radiant power thus allows a fully consistent and trustworthy design of photoreactors.http://dx.doi.org/10.1155/IJP/2006/26870 |
| spellingShingle | Ignazio Renato Bellobono Giulia de Martini Paola Maria Tozzi Carmen Canevali Franca Morazzoni Roberto Scotti Riccardo Bianchi Modelling of quantum yields in photocatalytic membrane reactors immobilising titanium dioxide International Journal of Photoenergy |
| title | Modelling of quantum yields in photocatalytic membrane reactors immobilising titanium dioxide |
| title_full | Modelling of quantum yields in photocatalytic membrane reactors immobilising titanium dioxide |
| title_fullStr | Modelling of quantum yields in photocatalytic membrane reactors immobilising titanium dioxide |
| title_full_unstemmed | Modelling of quantum yields in photocatalytic membrane reactors immobilising titanium dioxide |
| title_short | Modelling of quantum yields in photocatalytic membrane reactors immobilising titanium dioxide |
| title_sort | modelling of quantum yields in photocatalytic membrane reactors immobilising titanium dioxide |
| url | http://dx.doi.org/10.1155/IJP/2006/26870 |
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