Synthesis and Characterization of Cobalt Oxide Nanoparticles

The present work reports the synthesis and characterization of cobalt oxide nanoparticles. Microwave oven method was used for synthesizing cobalt oxide nanoparticles. The synthesized nanoparticles were characterized by X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), UV-Vis spectroscopy, photoluminescence (PL) and scanning electron microscope (SEM). The prepared samples show poor crystalline nature so that the samples were calcined at 300 °C for 1 hr. The calcined samples were characterized for further changes in its morphology. XRD identifies the sample is in Co3O4 phase with face-centered cubic structure. Debye-Scherer formula was used to calculate the average crystallite size of the annealed sample and it was found to be 7 to 28 nm. In addition to crystallite size, specific surface area, dislocation density and microstrain are calculated using XRD. Williamson-Hall plot was used to calculate the size and strain. FT-IR spectrum shows two stretching bands at 660 and 550 cm−1 which confirm the functional group present in the cobalt oxide nanoparticles. In optical absorption studies, a blue shift in the energy band gap reveals the quantum confinement effect. Photoluminescence spectra shows emission peak in the visible region.