Coordination polymer-derived CuO catalysts for oxidative degradation of methylene blue

Abstract

Coordination polymers (CP) are a new class of hybrid materials consisting of metal clusters connected by organic ligands and forming structures along one, two or three dimensions. Three Cu2+ coordination polymers Cu(1,3-BDC).3H2O, Cu(1,4-BDC), and Cu(5-NH2-1,3-BDC) (BDC = benzenedicarboxylic) were prepared via an electrochemical method and used as precursors for CuO by calcination in air at 650 °C. All the prepared samples were characterized by Powder X-ray Diffraction (PXRD), Attenuated Total Reflectance Fourier Transform Infrared spectroscopy (ATR-FTIR), Thermal Analysis (TGA-DTA), and Scanning Electron Microscopy (SEM). The results confirmed both the crystallization of the CPs and the formation of copper oxide after the thermal treatment. The CP-derived CuO was tested in the catalytic degradation of the methylene blue in the presence of H2O2, and the effect of reaction parameters such as the mass of catalyst and volume of H2O2 were studied. Cu(1,4-BDC)-derived CuO catalyst showed discoloration efficiency about 92% at 308 K, and 100% at 331 K after 120 and 30 min, respectively with good recyclability up to the four cycles (71.77%).