Self-assembled Cube-like Copper Oxide Derived from a Metal-Organic Framework as a High-Performance Electrochemical...

Interest in pseudocapacitive materials, especially cuprous oxide, has grown owing to its various advantageous properties and application as electrode materials in the energy storage devices. The work presented here, a cubic Cu₂O framework was synthesized using a simple and one-step modified polyol-assisted (metal-organic framework) solvothermal method. The structural configuration was rationalized by systematically studying the effect of the reaction time on the morphology and growth of the Cu₂O. In addition, a range of microscopic and spectroscopic techniques was employed to further characterize the obtained cubic Cu₂O. The morphological effect on the electrochemical supercapacitive performance of the obtained cubic Cu₂O was also examined by cyclic-voltammetry (CV) and galvanostatic-charge-discharge (G-C-D) method. The obtained outcome shows that the cubic Cu₂O synthesized using a reaction time of 12 h (Cu₂O-12h; C_sp ~365 Fg^-1) exhibited superior capacitive performance as compared to the cubic Cu₂O synthesized at 8 h (Cu₂O-8h; C_sp ~151 Fg^-1) and 10 h (Cu₂O-10h; C_sp ~195 Fg^-1) at the current density of 0.75 Ag^-1. Furthermore, the Cu₂O-12h electrode exhibits energy density of 16.95 Wh/Kg at a power density of 235.4 W/Kg and higher power density of 2678.5 W/Kg at low current density. In particular, the cube-like Cu₂O-12h exhibited excellent capacitive performance and rate capability as compared to Cu₂O-8h and Cu₂O-10h, owing to its unique three-dimensional morphology, which facilitates the formation of various active sites for intercalation of the electrolyte during the electrochemical process. These results show the as-obtained Cu₂O could be a promising supercapacaitive electrode material for various applications.