Enhanced photocatalytic degradation of methylene blue dye using CuO nanoparticles from the fruit extracts of Diplocyclos palmatus (L) C. Jeffrey for wastewater remediation

Abstract

ABSTRACT The degradation of synthetic organic dyes through photocatalysis requires structured nanoparticles (NPs). Copper oxide (CuO) NPs were used as the newest developed catalyst for the organic dye degradation under the irradiation of sunlight: The metal oxide NPs were synthesized using the fruit extract of Diplocyclos palmatus (L) C. Jeffrey. UV–visible light spectra showed an absorption band for CuO NPs at 277 nm. X-ray diffraction confirmed the monoclinic phase of CuO NPs. Scanning electron microscopy confirmed rod-shaped stacked particles. Energy-dispersive X-ray spectra indicating the presence of Cu in oxide form. For the degradation of methylene blue dye (MB), CuO NPs were used as photocatalyst for dye degradation under sunlight irradiation. This study confirmed the effects, such as irradiation time, concentration, pH, and catalyst dosage. The CuO NPs showed high photocatalytic degradation, degrading 90% of the dye in 120 min. The increased degradation of dye was observed on exposure to longer irradiation time. The increased concentration of dye resulted in a decreased rate of photodegradation. 95% degradation achieved at pH 9 showing that the pH medium also enhances the degradation. A higher dye degradation percentage was achieved by increasing the higher catalyst dosage of 0.013 g degraded 93% of dye. Thus in the treatment of wastewater containing pollutants, the synthesized CuO NPs acted as an efficient photocatalyst.