Synthesis and characterization of mesoporous crystalline copper metal–organic frameworks for electrochemical energy storage application

Abstract

The mesoporous nanostructure Cu-metal organic frameworks (Cu-MOF-1 and Cu-MOF-2) have been synthesized by a high temperature solvothermal route. The products were characterized by X-ray diffraction, Brunauer–Emmett–Teller surface measurement, Thermo gravimetric analysis, scanning electron microscope and Single crystal XRD. The electrochemical properties of these MOF electrodes were examined by using of cyclic voltammetry (CV), galvanostatic charge–discharge (GCD) and electrochemical impedance spectroscopic techniques. Comparing the results of CV and GCD studies, both those MOFs have shown significant charge storage capacity, while Cu-MOF-2 has showed a specific capacitance greater than Cu-MOF-1. The Cu-MOF-1 and Cu-MOF-2 electrodes showed a maximum specified capacity of 181 and 248 F g−1 respectively at a current density of 1 A g−1 and an extensive cyclic stability of up to 2000 cycles with capacity retention of ~ 90.1%. The electrochemical studies with Cu-MOF electrodes were conducted in 6 M KOH electrolytes. The excellent electrochemical properties of Cu-MOFs can be credited to the large surface area with a high microporous volume of structurally implanted electro-active metallic centres and the rapid transport of ions into electrolytes/electrodes. The results imply that the Cu-MOFs electrode could be the potentially high- performance electrode materials for super capacitor applications.