FACILE SYNTHESIS OF HOLLOW Co_3O_4 MICROSPHERES BY SOLUTION SPRAY-OXIDATION METHOD AND ITS PROPERTIES AS SUPERCAPACITORS

摘要

The hollow Co_3O_4 microspheres were synthesized by solution spray-oxidation method. The feed solution was prepared by using CoCl_2·6H_2O as raw materials, sprayed by using inner mixed air-nozzle and roasted in the erective tubular resistance furnace with compressed oxygen as carrier gas. The as-prepared samples were characterized by FT-IR, XRD and SEM techniques. The results show that the reaction temperature has an important impact on micro-structure and purity during the process of spray and oxidization for cobalt chloride solution, and the hollow Co_3O_4 microspheres were obtained at 700°C. Furthermore, the electrochemical tests show that the electrode prepared by the samples exhibits distinct characteristic of capacitance, the electrochemical capacitive properties of the hollow Co_3O_4 microspheres were evaluated using cyclic voltammetry and AC impedance methods. The capacitive properties depict that the Co_3O_4 synthesized by spray-oxidation method is capable of exhibiting excellent capacitive performance in 3.0 mol L~(-1) KOH electrolytes.