LAUSR

Abstract In order to treat the organic pollutants like dyes in water bodies, the environmentally benign nanoparticles are used extensively. The nanoparticles preparation by green chemistry approach is advantageous for this purpose. The Cu2O nanoparticles (NPs) were synthesized here by using Cu(NO3)2 and T. arjuna bark extract (as reducing and capping agent) under microwave irradiation. They were characterized by X-ray diffraction (XRD), Fourier transform infrared spectra (FT-IR), BET surface area and UV–vis spectra. The adsorption of methylene blue (MB) on Cu2O NPs in light and dark condition was found to be about 63% and 55%, respectively. The adsorption followed Langmuir isotherm, Freundlich isotherm and pseudo second order kinetics. The photo induced degradation of MB dye in presence of Cu2O NPs was also studied using photocatalytic reactor having UV lamp (250 W). Up to 97% degradation of MB occurred as monitored from UV–vis spectra. The degradation of MB was confirmed by HPLC and LC–MS analysis.