Synthesis Of Spherical Cobalt Oxide Nanoparticles By A Polyol Method

We report the synthesis of spherical cobalt oxide nanoparticles by a polyol method. To obtain spherical nanoparticles, water, polyvinylpyrrolidone (PVP), and cobalt acetate tetrahydrate were mixed in diethylene glycol and refluxed at 200 degrees C. Spherical particles were not obtained in the absence of water or PVP, or when the mixture was refluxed at 180 degrees C. The spherical nanoparticles were found to be composed of cobalt (II) oxide (CoO) with a small amount of cobalt oxyhydroxide (CoOOH). The synthesized spherical nanoparticles had good dispersibility in water, and Fourier transform infrared spectroscopy and thermogravimetrydifferential thermal analysis measurements indicated that the nanoparticles had a core-shell structure, with a core of CoO and a polymer shell. (C)2017 The Ceramic Society of Japan. All rights reserved.