Cadmium oxide (CdO) and cobalt oxide (Co₃O₄) nanoparticles were synthesized via a simple and cost-effective co-precipitation method under identical experimental conditions. The structural and morphological properties of the prepared nanomaterials were investigated using X-ray diffraction (XRD) and field emission scanning electron microscopy (FE-SEM). XRD analysis confirmed the formation of phase-pure cubic CdO and spinel Co₃O₄ without detectable secondary phases. The calculated crystallite sizes were 34.48 nm for CdO and 28.10 nm for Co₃O₄, indicating that Co₃O₄ formation favours finer crystallite growth under similar synthesis parameters. FE-SEM observations revealed nearly spherical particles with moderate agglomeration in both samples. The smaller crystallite size of Co₃O₄ suggests a higher nucleation rate and comparatively restricted grain growth relative to CdO. The comparative analysis demonstrates that precursor selection significantly influences crystallinity and particle size evolution even under identical preparation conditions. These findings provide insight into controlled metal oxide nanoparticle synthesis and highlight the suitability of the adopted method for scalable production of functional oxide nanomaterials.

Keywords: CdO Nanoparticles; Co₃O₄ Nanoparticles; Co-Precipitation;