Controlled Synthesis and Electrochemical Properties of Co_3O_4 Hierarchical Nanostructures from an Urchinlike Cobalt-Hydroxide-Carbonate Precursor

摘要

A large number of hierarchical Co_3O_4 nanostructures have been prepared via the thermal treatment of an urchinlike cobalt-hydroxide-carbonate precursor, which was obtained by simple hydrothermal treatment of CoCl_2 solution in the presence of urea and K_2SO_4. The as-obtained cobalt-hydroxide-carbonate precursor has been characterized by XRD, SEM, TEM, XPS, IR and TGA. To study the formation process of this urchinlike precursor, the influences of experimental parameters, such as reaction time and inorganic salts, etc., on the morphology have been investigated during the synthesis. It was found that the morphology of cobalt-hydroxide-carbonate was strongly dependent on the sulfate. Calcination of the precursor at 350℃ led to the formation of well-defined hierarchical Co_3O_4 nanostructures with a surface area of 60 m~2 g~(-1). The electrochemical properties of Co_3O_4 nanostructures were also investigated.