Simple thermal decomposition route to size-tunable cobalt(II) oxide and cobalt(II,III) oxide nanoparticles for nanoelectronic devices

Abstract

The present article a simple and controllable method for synthesizing cobalt oxide nanoparticles (CoO and Co₃O₄) with adjustable particle dimensions and morphologies. Cobalt glycerolate was first obtained by refluxing cobalt nitrate and glycerol for four hours, then thermally decomposed at 450–650oC under a mixed oxygen/nitrogen atmosphere for one hour to produce cobalt oxide nanoparticles. The structural phases and crystallite sizes were investigated using X-ray diffraction (XRD) and calculated via the Scherrer equation, while investigated and scanning electron microscopic examination (TEM and SEM) confirmed particle shape, size distribution, and surface uniformity. By varying the decomposition temperature, both particle size and phase composition were effectively controlled—lower temperatures favoring smaller CoO nanoparticles and higher temperatures producing larger, well-crystallized Co₃O₄ particles. The resulting nanoparticles exhibit uniform morphology, high crystallinity, and controllable dimensions, making them suitable for diverse applications in lithium-ion batteries, chemical sensors, and nanoelectronic devices. This straightforward synthesis strategy offers an efficient and scalable route for tailoring cobalt oxide nanomaterials with desirable structural and functional properties.