Preparation of microsized single-crystalline Co₃O₄ by high-temperature hydrolysis

Abstract

Microsized single-crystalline Co₃O₄ has been synthesized by high-temperature hydrolysis of CoCl₂·2H₂O at 600 °C. The samples were characterized by powder X-ray diffraction (XRD), scanning electron microscopy (SEM) and transmission electron microscopy (TEM). The results reveal that the as-prepared powders are microsized single-crystalline Co₃O₄ with cubic spinel structure. An increase in the high-temperature hydrolysis time results in the evolution of particle shapes from cube to quasi-sphere, and then to octahedron. The effect of NaCl additive on the surface morphologies of Co₃O₄ particles was experimentally investigated. The results indicate that the NaCl additive acts as an inert disperse phase in the high-temperature hydrolysis, and prevents the aggregation of Co₃O₄ particles effectively.

Keywords

Co₃O₄ / crystal structure / hydrolysis / surface morphology