943-948The heterogeneous photo-Fenton degradation of coomasie brilliant
blue R–250 under visible light has been investigated using copper modified iron
oxide, which has been prepared by coprecipitation method and characterized by
IR spectroscopy, scanning electron microscopy and X-ray diffraction. The rate
of photocatalytic degradation of dye follows pseudo-first order kinetics. The
effects of various parameters like pH,
concentration of dye, amount of photocatalyst, amount of H2O2
and light intensity on the rate of the photo-Fenton degradation has also been
studied. Chemical oxygen demand of the reaction mixture before and after
exposure has been determined. A tentative mechanism for the photocatalytic
degradation has been proposed, wherein involvement of •OH radicals
has been confirmed by the drastic reduction in the reaction rate in the
presence of •OH radical scavengers such as isopropanol and butylated
hydroxy toluene. The retardation with butylated hydroxy toluene is much higher
than with isopropanol. Under similar conditions, efficiencies of Fe2O3
and copper modified Fe2O3 have been compared for
the photocatalytic degradation of coomasie brilliant blue R-250