CuO as efficient photo catalyst for photocatalytic decoloration of wastewater containing Azo dyes

Abstract

Abstract Cupric oxide nanoparticles (CuO NPs) were prepared via a chemical precipitation method using the precursor of copper (II) nitrate trihydrate. X-ray diffraction analysis confirms that the CuO NPs were a monoclinic crystal structure. The energy band gap of CuO NPs was found to be about 1.76 eV. The obtained CuO NPs were used as a photo catalyst to decolorize various dyes, such as methylene blue (MB), acid yellow 23 (AY 23) and reactive black 5 (RB 5), with a low concentration in the presence of visible light. The results show that the highest decolorization achieved was 67.8% and 66.3% for RB-5 dye and AY-23 dye, while 43.5% for MB dye from aqueous solution at 5 h illumination. The obtained CuO NPs were used as a photo catalyst to decolorize various dyes, RB-5, AY-23 and MB dye obeys pseudo first order kinetics with values of −0.112, −0.174 and −0.201 h−1, respectively.