Morphology-controlled synthesis of porous Co3O4 nanostructures by in-situ dealloying and oxidation route for application in supercapacitors

Synthesis of electrode materials with desirable morphology and size for supercapacitor applications is an important and challenging research topic. In this work, four types of Co3O4 nanostructures, namely hexagonal-shaped nanosheets, nanoflake arrays, nanoflowers and oval-shaped nanospheres were synthesized via a facile in-situ dealloying method. Applied as electrode material for supercapacitiors, the Co3O4 nanospheres achieves highest areal capacitance of 16.58 F cm−2 at current density of 10 mA cm−2. The Co3O4 nanoflowers exhibited promising capacitive properties and excellent retention. Its areal capacitance can reach 9.27 F cm−2 at the current density of 10 mA cm−2 and retain 98.5% of its initial capacitance at the current density of mA cm−2 after 1000 charge–discharge cycles. This work could provide a deeper understanding of the morphology effect on the supercapacitive performance, and also suggests the importance of rational design and synthesis of electrode materials with desirable morphology and size for high performance supercapacitor applications.