PHOTOCATALYTIC ACTION OF ZINC FERRITE AND ZNO/ZINC FERRITE FILMS IN THE DEGRADATION OF REACTIVE BLACK 5

In recent years, semiconductor photocatalysts are widely used to degrade a large number of chemicals and organic pollutants. Here the photocatalytic degradation of the commercial textile dye Reactive Black 5 has been investigated in aqueous solutions, under UV-light, visible illumination and in complete darkness. In this study, we used for the first time ZnO/ZnFe2O4 as photocatalysts in the form of films. Zinc ferrite and ZnO/ZnFe2O4 films were obtained on glass substrates by sol-gel method via dip coating technique. The films are characterized by means of scanning electron microscopy, X-ray diffraction and UV-visible spectroscopy. Their photocatalytic properties were investigated and compared at different initial dye concentration (3, 5 and 10 ppm). The experimental results showed that pure ZnFe2O4 films have lower photocatalytic efficiency in RB5 dye decolourization than those mixed with ZnO. Nevertheless, all films exhibit a substantial activity under both types of irradiation - UV and visible light and in darkness as well, which is promising for the development of new photocatalysts, obtained by the sol-gel method.