Synthesis of Co 3O 4 nanostructures using a solvothermal approach

Abstract

The controlled synthesis of Co 3O 4 nanostructures with morphologies of micro-spheres, nanobelts, and nanoplates was successfully achieved by a simple solvothermal method. Various comparison experiments showed that several experimental parameters, such as the reaction temperature and the concentration of NH 3·H 2O, play important roles in the morphological control of Co 3O 4 nanostructures. A lower temperature and a lower concentration of NH 3·H 2O favor spherical products with a diameter of 1–1.5 μm, whereas a higher temperature and a higher concentration of NH 3·H 2O generally lead to the formation of nanobelts with a width of 20–150 nm. In addition, Co 3O 4 hexagonal nanoplates with an edge length of about 200–300 nm are also obtained by adding surfactant CTAB. A rational mechanism is proposed for the selective formation of various morphologies. X-ray powder diffraction (XRD), transmission electron microscopy (TEM), selected-area electron diffraction (SAED), and field-emission scanning electron microscope (FE-SEM) were used to characterize the products.