Despite growing interest in metal oxide nanomaterials, there remains a notable lack of systematically engineered iron oxide (Fe2O3) and magnesium oxide (MgO) nanoparticles with well-defined structural and surface properties tailored for safe, multifunctional use in agriculture and environmental remediation. This study comprehensively evaluates the synthesis and characterization of Fe2O3 and MgO nanoparticles, revealing their successful formation with controlled crystallinity, morphology and surface functional groups. X-ray diffraction (XRD) analysis confirmed the nanocrystalline structures and high purity of both nanoparticles. Magnesium oxide showed sharp, well-defined peaks indexed to the cubic phase (JCPDS card no. 45-0946 with crystallite sizes 18-25 nm) using the Scherrer equation. The Fe2O3 nanoparticles displayed sharp phase-specific peaks with crystallite sizes ranging from 20 to 35 nm, demonstrating their high purity and crystallinity. Fourier-transform infrared (FTIR) spectroscopy identified characteristic functional groups, including surface hydroxyls and metal-oxygen stretching vibrations. Mg-O (~411 cm-1) and Fe-O bands confirmed reactive nanostructures. Transmission electron microscopy (TEM) images revealed
predominantly hexagonal MgO nanoparticles sized 20-40 nm with sharp boundaries indicating low defects, while Fe2O3 nanoparticles exhibited near-spherical to polyhedral morphologies ranging from 23 to 64 nm, with moderate agglomeration attributed to magnetic interactions. These well-controlled nanostructures, with high surface area and reactivity, are promising candidates for agricultural and environmental applications, nanofertilizers, plant virus management, catalysis and remediation.