Preparation and application of mixed ligand Zn-MOF as electrode materials for supercapacitors applications

In this study, various mixed-linker metal-organic frameworks (MOFs) based on Zn-MOF were successfully synthesized using different ratios of 1,3,5-benzenetricarboxylic acid (BTC) and 1,4-benzenedicarboxylic acid (BDC) as modulator ligands. The characterization results indicated that a lower percentage of BDC ligand effectively enhances the specific surface area of the MOFs while maintaining their microporous structure. Furthermore, the supercapacitive behavior of the synthesized Zn-MOFs with varying mixed ligand ratios was evaluated through electrochemical impedance spectroscopy (EIS), cyclic voltammetry (CV), and galvanostatic charge-discharge (GCD) measurements in a 6 M KOH electrolyte. Synthesized materials, namely MOF-0 (100% BTC), MOF-1 (75% BTC, 25% BDC), MOF-2 (50% BTC, 50% BDC), MOF-3 (25% BTC, 75% BDC), and MOF-4 (100% BDC) were assessed through GCD tests. These tests demonstrated specific capacitance values of 577, 683, 529, 428, and 302 F/g at a current density of 0.5 A/g, respectively. This impressive performance underscores the effectiveness of the mixed-linker strategy in optimizing the electrochemical properties of MOF for energy storage applications.