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...
Saved in:
| Main Authors: | , , , , , , |
|---|---|
| Format: | Article |
| Language: | English |
| Published: |
Wiley
2006-01-01
|
| Series: | International Journal of Photoenergy |
| Online Access: | http://dx.doi.org/10.1155/IJP/2006/26870 |
| Tags: |
Add Tag
No Tags, Be the first to tag this record!
|
| Summary: | 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. |
|---|---|
| ISSN: | 1110-662X 1687-529X |