Biological Synthesis of Cobalt Nanoparticles from Mangifera indica Leaf Extract and Application by Detection of Manganese (II) Ions Present in Industrial Wastewater

This study was focused on the synthesis of cobalt nanoparticles using Mangifera indica leaf extract and the characterization of the particles via UV–Vis spectroscopy, XRD, FT-IR and SEM. The XRD results showed the formation of cobalt nanoparticles that was crystalline in nature, with an average size of 25—40 nm. The FT-IR analysis of the leaf extract reviewed some functional groups responsible for the reduction of cobalt ions to cobalt nanoparticles while the SEM indicates that the synthesised cobalt nanoparticles possess a cubic, pentagonal and irregular in shape with a smooth surface. Application of colloidal cobalt nanoparticles in detecting Mn2+ ions was discussed which indicated that the absorption of the Mn (II) ions decreased at increased concentration of Mn (II) ions indicating that Mn (II) ion can be detected even at a very low concentration. The minimum and maximum detection limit was found to be 5 and 25 mM of Mn (II) ions, respectively. The obtained results encourage the use of economical synthesis of cobalt nanoparticles in the development of nanosensors to detect the pollutants present in industrial effluents.