Structural, DFT and redox activity investigation of 2D silver based MOF for energy storage devices

A new silver(I) 2D MOF (Ag-MOF) was synthesized from 3,4-pyridinedicarboxylic acid (PDCA) by sonication method and characterized by single crystal X-ray diffraction, elemental analysis and FTIR spectroscopy. The material was further utilized for DFT computation and electrochemical performance. Theoretical and practical results for Ag-MOF geometrical parameters were found to be in reasonable agreement. Small HOMO-LUMO energy distance of 0.47 eV confirmed that electron transfer was much feasible. Distribution of electron isodensities was elaborated by DFT and FMOs computation. Double redox peaks in CV voltammograms reflected the change in oxidation state. Multiple plateaus in GCD curves showed the pseudo-capacitive behavior. Ag-MOF exhibited 101 Cg−1 specific capacity (Qs), 123 Wh.kg−1 energy density and 12,960 W kg−1 power density at current density of 5 Ag−1. There was a small difference in Rct and Ri which revealed that Ag-MOF had great ability to store energy. Presence of semi-circular arc in the EIS spectrum directly dictates the supercapacitor behavior. The electrode showed 97.5 % cyclic stability after 5000 cycles.