Ecological fabrication of copper oxide nanoparticles for enhanced photocatalytic degradation of methylene blue and rhodamine B. Dye

Abstract

Industrial wastewater has been an alarming issue that can have harmful effects on humans and the environment. Numerous treatment methods have been introduced to reduce toxicity, but photocatalyst treatment has been gaining interest because of its environmental behavior. This study used Grewia asiatica L. extract, which was not previously utilized to synthesize the copper oxide nanoparticles; various spectroscopic and microscopic techniques were used to characterizesynthesized nanoparticles. The UV–visible spectrophotometer spectra showed an absorbance peak at 248 nm that confirmed the synthesis of copper oxide nanoparticles. Similarly, the scanning electron microscope (SEM) and X-ray Diffraction (XRD) revealed that the synthesized nanoparticles have a size of 33.71 nm and are spherical. The energy dispersive x-ray (EDX) spectra showed the sample's elemental composition, in which copper and oxygen are present in high percentages. The Fourier infrared spectrophotometer (FTIR) spectra confirmed the fundamental biomolecules that have reduced and stabilized the copper oxide nanoparticles. The synthesized nanoparticles were developed as a catalyst under solar radiation to reduce methylene blue and rhodamine B dyes. Methylene blue was degraded 92% in 25 min with a 0.0397 min−1 rate constant. The Rhodamine B dye was degraded 98% in 50 min with a rate constant of 0.0198 min−1. Results revealed that Grewia asiatica L. mediated copper oxide nanoparticles can be used as a wastewater treatment catalystto reduce toxic dyes.