Heterogeneous photo-Fenton-like catalysts Cu₂V₂O₇ and Cr₂V₄O₁₃ for an efficient removal of azo dye in water

Abstract

This work deals with the degradation of non-biodegradable azo-dye (Evans blue) by the heterogeneous photo-Fenton-like process using copper pyrovanadate (Cu2V2O7) and chromium tetravanadate (Cr2V4O13) as catalysts, which have been prepared by wet chemical method. These catalysts were characterized by different techniques such as scanning electron microscopy, X-ray diffraction, Fourier transform infrared spectroscopy, and Brunauer–Emmett–Teller surface area analysis. The effect of various parameters such as initial pH, concentration of dye, amount of catalyst, amount of H2O2, and light intensity on the reaction rate has also been studied. Photodegradation efficiency was found 77.78 and 79% for copper pyrovanadate (Cu2V2O7) and chromium tetravanadate (Cr2V4O13), respectively. A tentative mechanism involving ·OH radicals as an oxidant for the degradation of dye has also been proposed. The observations revealed that the rate of photo-Fenton-like degradation of dye follows pseudo-first-order kinetics.