Facile morphology controlled synthesis of nanostructured Co3O4 films on nickel foam and their pseudocapacitive performance

Abstract

Nanostructured transition metal oxides are a current investigation focus for supercapacitors. We herein report a facile solvothermal synthesis of nanostructured Co₃O₄ films on nickel foam. The morphologies and dimensions of the Co₃O₄ films can be effectively tuned by tailoring the solvent compositions in the solvothermal reaction solutions. The effect of solvent composition on the morphologies of nanostructured Co₃O₄ films is analyzed. The 3D hierarchically porous Co₃O₄ network film, which is synthesized in the solvothermal reaction solution with an intermediate ethylene glycol/water volume ratio (1 : 29), shows a markedly enhanced pseudocapacitive performance. The specific capacitances of the Co₃O₄ network film electrode at the current densities of 0.870 and 17.391 A g⁻¹ are 2817 and 1948 F g⁻¹, respectively, revealing its large specific capacitance and excellent rate capability. Furthermore, the Co₃O₄ network film electrode exhibits good electrochemical cycling stability with a specific capacitance of 1628 F g⁻¹ after 3500 cycles at a current density of 4.348 A g⁻¹. The prominent pseudocapacitive performance of the Co₃O₄ network film electrode can be attributed to its unique structural characteristics. The as-synthesized 3D hierarchically porous Co₃O₄ network film with excellent pseudocapacitive performance demonstrates promising potential as a high-performance electrode for supercapacitors.