Solvent-assisted ligand exchange as a post-synthetic surface modification approach of Zn-based (ZIF-7, ZIF-8) and Co-based (ZIF-9, ZIF-67) zeolitic frameworks for energy storage application

In this research, we tried to change in overall ZIF structure by adding another linker via post-synthetic solvent-assisted ligand exchange (SALE) and investigated the energy storage properties as a supercapacitor. To identify materials, these analyzes were performed, such as PXRD to confirm the structure of four hybrids ([email protected], [email protected], [email protected], and [email protected]). The functional groups of each ligand were identified using FT-IR and 13C NMR. SEM images confirm the material morphology and the EDX spectrum for the distribution of elements in the structures as well as for supercapacitor application. These studies used KOH 6 M as the electrolyte and included cyclic voltammetry (CV), galvanostatic charge–discharge (GCD), and electrochemical impedance spectroscopy (EIS). As the best compound, [email protected], at a current density of 3 A/g, had a high specific capacitance of 300 F/g. The following section covers how to construct an asymmetric supercapacitor using activated carbon as a negative electrode and a [email protected] as a positive electrode. In current densities of 1 and 20 A/g, this device can supply specific energy up to 8.1 Wh/kg and specific power of 16 kW/kg and retains 89 % of its capacitance after 3000 cycles.