Role of copper pyrovanadate as heterogeneous photo-Fenton like catalyst for the degradation of neutral red and azure-B: An eco-friendly approach

The heterogeneous photo-Fenton like process is a green chemical pathway. It has an edge over conventional Fenton and photo-Fenton processes as it does not require the removal of ferrous/ferric ions in the form of sludge. We prepeared copper pyrovanadate or Volborthite (Cu3V2(OH)(2)O(7)a (TM) 2H(2)O) composite photocatalyst by wet chemical method. The photocatalyst was characterized by SEM, XRD, IR, TGA/DSC, EDX and BET. Experiments demonstrated that catalyst could effectively catalyze degradation of neutral red and azure-B in presence of H2O2 in visible light. Moreover, the photo-Fenton-like catalytic activity of Cu3V2(OH)(2)O(7)a (TM) 2H(2)O was much higher than CuO and V2O5, when used alone as photocatalyst. The effect of variation of different parameters, i.e., pH, amount of photocatalyst, concentration of dye, amount of H2O2 and light intensity was also investigated. The degradation was well fitted under pseudo-first-order reaction with a rate constant of 2.081x10(-4) sec(-1) and 3.876x10(-4) sec(-1) for neutral red and azure-B, respectively. Quality parameters of dye solutions before and after photo-Fenton degradation were also determined. A tentative mechanism involving (OH)-O-aEuro cent radical as an oxidant has been proposed. The high catalytic activity may be due to the Cu3V2(OH)(2)O(7)a (TM) 2H(2)O shell, which not only increased the surface hydroxyl groups, but also enhanced the interfacial electron transfer. The catalyst has been found to possess good recyclability.