Microsized single-crystalline Co3O4 has been synthesized by high-temperature hydrolysis of CoCl2·2H2O at 600 ℃.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 patricles 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.