(Digital Presentation) Synthesis and Characterization of ZIF-8@ZIF-67 Bimetallic MOF for Supercapacitor Applications

Abstract

Metal-organic frameworks (MOFs) are the attractive materials for energy storage applications because of its distinctive properties like high porosity, structural flexibility, high specific surface area, good stability etc. However, their low conductivity motivates to incorporate with some conductive matrix in a way to produce conductive and porous composite. Herein, we have synthesized Zeolitic imidazolate frameworks (ZIFs)-based core–shell structured nanomaterials. The bimetallic MOF consisting of ZIF-8@ZIF-67 core-shell structure is synthesized and the formation of ZIF-8@ZIF-67 structure is further confirmed by XRD, Raman, FTIR, BET and FESEM characterizations. The as prepared electrode material shows very high specific surface area and hierarchical porous morphology, therefore becomes suitable to be used as an active electrode material for supercapacitors application. Furthermore, the ZIF-8@ZIF-67 shows superior electrochemical performance using 1M Na2SO4, Redox electrolyte and water in salt electrolyte (WiSE) in a three-electrode system. The as-prepared electrode material shows high specific capacitance and long cycle life as compared to their pristine electrode counterparts. Therefore, this work paves the way for the utilization of various bimetallic MOFs to improve the conductivity of pristine MOFs in a way to utilize as an appropriate electrode material for next generation energy storage devices. Keywords: ZIF, Water in salt electrolyte, Porosity, Redox electrolyte, Supercapacitor