We found a match
Your institution may have rights to this item. Sign in to continue.
- Title
Modelling of Quantum Yields in Photocatalytic Membrane Reactors Immobilising Titanium Dioxide.
- Authors
Bellobono, Ignazio Renato; de Martini, Giulia; Tozzi, Paola Maria; Canevali, Carmen; Morazzoni, Franca; Scotti, Roberto; Bianchi, Riccardo
- Abstract
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 Φ0, 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.
- Subjects
MEMBRANE reactors; TITANIUM dioxide; RADIATION; HYDROXYL group; HYDROGEN peroxide; BIOREACTORS
- Publication
International Journal of Photoenergy, 2006, p1
- ISSN
1110-662X
- Publication type
Article
- DOI
10.1155/IJP/2006/26870