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

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 similar to 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.