Green synthesis of ZnO and Co-ZnO using Brassica rapa leave's extract and their activities as antioxidant agents, efficient adsorbents, and dye removal agents

The wastewater released from industries contains many harmful materials like organic dyes and toxic metal ions which badly affect our environment. Nanotechnology is one of the unique approaches to reducing these chemicals. In current research work monometallic ZnO and Co-ZnO bimetallic NPs were synthesized from Brassica rapa leave's extract and then these were employed for the elimination of methylene blue (MB) and metal ions of Cu (II). Characterization was done by several analytical techniques such as EDX, FTIR, UV–Visible spectroscopy, SEM and XRD. The average diameter of ZnO and Co-ZnO BMNPs was found to be 32.94 nm and 13.82 nm assessed by XRD analysis. The SEM investigation revealed that the produced NPs had a spherical shape. Three distinct methods have opted to determine the antioxidant potential of synthesized NPs. Different factors like pH, contact time, NPs conc., dye conc. and temperature were studied for the elimination of dye while for the eradication of Cu (II) ions; pH, contact time, NPs conc. and adsorbate doses were studied. Adsorption isotherm and kinetic studies were employed for MB and Cu (II) ions elimination while thermodynamic studies were also done for the elimination of MB.