- Saturday, December 8, 2007
- DYE-EFFECT IN TiO2 CATALYZED CONTAMINANT PHOTODEGRADATION: SENSITIZATION VS. CHARGE-TRANSFER FORMALISM
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H. S. Hilal1*, L. Z. Majjad1, N. Zaatar1 and A. El-Hamouz2,
1Department of Chemistry,2Department of Chemical Engineering, An-Najah N. University, PO Box 7, Nablus, Palestine
Solid State Sciences, 9(2007)9-15.
* Corresponding author: Fax: +-970-9-287 982 E-mail: [email protected]
Anatase TiO2 surfaces have been treated with 2,4,6-triphenylpyrilium hydrogen sulfate (TPPHS) dye to yield the modified TiO2/TPPHS surface. The modified TiO2/TPPHS surface was then supported onto activated carbon (AC) surfaces to yield a new class of catalytic system AC/TiO2/TPPHS. The catalytic activities of naked TiO2, TPPHS solution, TiO2/TPPHS and AC/TiO2/TPPHS systems were examined in photo-degradation of phenol and benzoic acid in water, using both UV and visible regions. All studied systems showed low catalytic activity when used in the visible. In UV, the AC/TiO2/TPPHS showed highest activity, whereas the naked TiO2 and TPPHS solution were the least active systems. The dye role, in enhancing activity of modified surfaces in UV degradation of contaminants, is understandable by a charge transfer catalytic effect rather than a sensitizing effect. AC role is explainable by its ability to adsorb contaminant molecules and bringing them closer to catalytic sites