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

• Published in: The Korean journal of chemical engineering Vol. 31; no. 12; pp. 2183 - 2191
• Main Authors: Kalal, Sangeeta, Singh Chauhan, Narendra Pal, Ameta, Noopur, Ameta, Rakshit, Kumar, Sudhish, Punjabi, Pinki Bala
• Format: Journal Article
• Language: English
• Published: Boston Springer US 01.12.2014; 한국화학공학회
• Subjects: Biotechnology; Catalysis; Chemistry; Chemistry and Materials Science; Environmental Engineering; Industrial Chemistry/Chemical Engineering; Materials Science; 화학공학; Photo-Fenton; Heterogeneous; Neutral Red; Advanced Oxidation Processes; Azure-B; Mechanism
• ISSN: 0256-1115; 1975-7220
• DOI: 10.1007/s11814-014-0142-z

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 (Cu 3 V 2 (OH) 2 O 7 ∙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 H 2 O 2 in visible light. Moreover, the photo-Fenton-like catalytic activity of Cu 3 V 2 (OH) 2 O 7 ∙2H 2 O was much higher than CuO and V 2 O 5 , when used alone as photocatalyst. The effect of variation of different parameters, i.e., pH, amount of photocatalyst, concentration of dye, amount of H 2 O 2 and light intensity was also investigated. The degradation was well fitted under pseudo-first-order reaction with a rate constant of 2.081×10 −4 sec −1 and 3.876×10 −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 radical as an oxidant has been proposed. The high catalytic activity may be due to the Cu 3 V 2 (OH) 2 O 7 ∙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.