Controllable Synthesis of Mesoporous Co3O4 Nanostructures with Tunable Morphology for Application in Supercapacitors

Abstract

Flower power: Various mesoporous Co 3 O 4 architectural structures (see figure) have been successfully prepared through a facile binary‐solution route and sequential thermal decomposition at atmospheric pressure. The electrochemical experiments showed that the specific capacitance of Co 3 O 4 nanosheets was higher than that of Co 3 O 4 microspheres in a KOH electrolyte.magnified image Novel and complex mesoporous 2D and 3D architectures of the oxide semiconductor Co 3 O 4, including nanosheets, nearly monodisperse microspheres that are self‐assembled from nanosheets, and copper‐coin‐like nanosheets, have been synthesized through a facile binary‐solution route and sequential thermal decomposition at atmospheric pressure. The influence of different reaction conditions on the morphology of the products has been discussed in detail. The results revealed that the volume ratio of H 2 O and ethanolamine (EA) play a crucial role in the morphology of the precursor. The thermal decomposition of the corresponding precursor leads to the formation of the mesoporous structure. The products have been characterized by X‐ray diffraction techniques, field‐emission scanning electron microscopy (FESEM), transmission electron microscopy (TEM), high‐resolution TEM (HRTEM), and Raman spectroscopy. The electrochemical properties of the Co 3 O 4 electrodes were investigated by cyclic voltammetry (CV) and galvanostatic charge–discharge measurements. The electrochemical experiments revealed that the specific capacitance of the Co 3 O 4 nanosheets was higher than that of the Co 3 O 4 microspheres in a KOH electrolyte solution (3 m). Furthermore, the Co 3 O 4 nanosheet electrodes exhibited good rate capabilities, and maintained 93 % of the initial capacity at a current density of 5 mA cm−2 in a KOH (3 m) electrolyte solution. The results show that Co 3 O 4 nanosheets might have potential applications as electrode materials for supercapacitors.