Enhancement of electrochemical energy storage performance of MOF-5 and Eucalyptus plant bark derived rGO composite

Abstract Metal Organic Frameworks (MOFs) and carbon derivatives based composites are an interesting class of materials having complementary properties, with the high surface area and tunable porosity of MOFs together with excellent electrical conductivity of carbon based materials. Here in, we report a facile one step solvothermal synthesis of composite made of MOF-5 and Eucalyptus bark derived rGO. MOF-5/rGO composite (MRG) has a high specific surface area (1150 m 2 g −1 ). MRG was studied for electrochemical energy storage application using Cycle Voltammetry (CV), Galvanostatic Charge Discharge (GCD) and Electrochemical Impedance Spectroscopy (EIS). The MRG has high specific capacitance of 1366.6 F g −1 as calculated by GCD at 1 A g −1 current density, Energy density of 150.7 W h kg −1 and Power density of 450.3 W kg −1 at a current density of 1 A g −1 as calculated by GCD with 1 M H 2 SO 4 . The coulombic efficiency for the MRG composite was found to be 89.3% at higher current density. The cyclic stability data shown that composite material is retaining ∼80.9% capacitance even after 10000 cycles. Moreover, symmetrical two electrode device of MRG shown a specific capacitance of 262.4 F g −1 at a current density of 1 A g −1 , while the device retained 83.7% capacitance after 10000 charging discharging cycles. The energy density and power density of device were found to be 36.4 W h kg −1 and 498.6 W kg −1 at a current of 1 A g −1 . The enhanced electrochemical performance of MRG is attributed to the synergistic effect between MOF-5 and rGO leading to the enhanced conductivity and provides larger surface area for charge storage.