ABSTRACT
TiO2, ZnO and mixed TiO2+ZnO photocatalysts in the form of thin layers mounted on
2.5 x 2.5 cm glass sheets were prepared and tested for the photocatalytic
degradation of 25 ppm anthrecene in its aqueous solution using a medium-pressure
6W-UV lamp irradiating at a wave length of 254 nm as an irradiation source and a
reactor made of silica glass. Analysis of the produced intermediates and the
remaining anthracene after consecutive irradiation periods was achieved mainly by
HPLC and GC/MS spectroscopy. The catalysts were characterized by x-ray
diffraction (XRD) and scanning electron microscopy (SEM). The activities of the
current photo-catalysts were found to be in the order: TiO2 > ZnO > TiO2/ZnO. The
same intermediates formed in the photodegradation of anthracene using TiO2 and
ZnO catalysts are produced, whereas using the TiO2/ZnO catalyst most of these
intermediates disappear, probably due to difference in the adsorption/desorption
behaviours of these catalysts. Organic acids were the predominant intermediates on
all catalysts; they are the most resistive against photocatalytic degradation.