Green Cobalt Nanoparticle Synthesis, Characterisation, Magnetic Properties, and Phytostimulatory Impacts of Moringa oleifera Leaf Extract

The distinctive structural, chemical, magnetic, and biological characteristics of cobalt nanoparticles (CoNPs) have garnered significant interest. In this work, Moringa oleifera leaf extract and cobalt nitrate solution were used in an eco-friendly green synthesis method to create cobalt nanoparticles. The crystalline structure, functional groups, and magnetic behavior of the synthesized CoNPs were examined using X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), and vibrating sample magnetometry (VSM). Characteristic diffraction peaks were identified by XRD analysis with 2θ values of 36.2°, 43.1°, 50.4°, and 73.9°, corresponding to the (311), (400), (422), and (533) planes. The diffraction pattern matched JCPDS card No. 22-1086 and was compatible with the stated cubic spinel structure. The Scherrer equation yielded an average crystallite size of 18.37 nm. Along with Co–O-related vibrations, FT-IR analysis showed absorption bands at 3376, 1656, 591.99, and 495 cm⁻¹, suggesting the role of hydroxyl-containing and other functional groups in the production and stabilization of the nanoparticles. The produced CoNPs' magnetic nature was validated by VSM analysis. Canola plants were used to assess the synthesized nanoparticles' biological and agronomic applications. At lower concentrations, CoNP treatment increased shoot fresh weight, shoot dry weight, and shoot length; the greatest growth response was shown at 50 ppm. Plant growth decreased at higher doses, suggesting that CoNPs may have a concentration-dependent harmful impact. These results show that magnetic cobaltbased nanoparticles with potential uses in nanotechnology, agriculture, and biomedicine may be produced easily and sustainably by Moringa oleifera-mediated synthesis. These results show that magnetic cobalt-based nanoparticles with potential uses in nanotechnology, agriculture, and biomedicine may be produced easily and sustainably by Moringa oleifera-mediated synthesis.