Quick photo-Fenton degradation of phenolic compounds by Cu/Al2O3-MCM-41 under visible light irradiation: small particle size, stabilization of copper, easy reducibility of Cu and visible light active material

Abstract

The present study reports the photo-Fenton degradation of phenolic compounds (phenol, 2-chloro-4-nitrophenol and 4-chloro-2-nitrophenol) in aqueous solution using mesoporous Cu/Al2O3-MCM-41 nanocomposite as a heterogeneous photo-Fenton-like catalyst. The in situ incorporation of mesoporous Al2O3 (MA) into the framework of MCM-41 (sol-gel method) forms Al2O3-MCM-41 and wetness impregnation of Cu(II) on Al2O3-MCM-41 generates mesoporous Cu/Al2O3-MCM-41 composite. The effects of pH and H2O2 concentration on degradation of phenol, 2-chloro-4-nitrophenol and 4-chloro-2-nitrophenol are studied. Kinetics analysis shows that the photocatalytic degradation reaction follows a first-order rate equation. Mesoporous 5 Cu/Al2O3-MCM-41 is found to be an efficient photo-Fenton-like catalyst for the degradation of phenolic compounds. It shows nearly 100% degradation in 45 min at pH 4. The combined effect of small particle size, stabilization of Cu2+ on the support Al2O3-MCM-41, ease reducibility of Cu2+ and visible light activeness are the key factors for quick degradation of phenolic compounds by Cu/Al2O3-MCM-41.