Comparative Electrochemical Study of Tetra‐Carboxylate Linked Ni‐MOF and Cr‐MOF for Supercapacitor Application

Metal organic frameworks (MOFs) have emerged as promising electrode materials for supercapacitors owing to their high porosity, large specific surface area, structural tunability, and inherent redox activity. In the present work, an amorphous nickel‐based MOF (Ni‐MOF) and a low‐crystalline chromium‐based MOF (Cr‐MOF) were synthesized via a solvothermal route using a tetra‐carboxylate organic linker. The structural, chemical, and morphological features of the synthesized materials were examined using FT‐IR, PXRD, TGA, BET, XPS, and SEM. The Ni‐MOF exhibited a spherical morphology that facilitated electrolyte penetration and ion transport, whereas the Cr‐MOF displayed a fibrous compact structure, which limited electrolyte ion diffusion. The Ni‐MOF demonstrated a specific capacitance of 405 F g −1 at 1 A g −1 , significantly surpassing the capacitance of Cr‐MOF (48 F g −1 at 1 A g −1 ). In contrast, the Cr‐MOF showed superior cycling stability, retaining 87% of its capacitance after 1000 charge−discharge cycles, whereas the Ni‐MOF retained 40% after 500 cycles. The enhanced capacitance of Ni‐MOF is mainly attributed to the redox‐active nickel centers and improved charge‐transfer kinetics, while the chromium centers impart higher stability in Cr‐MOF. This work highlights the potential of amorphous‐like MOFs in supercapacitor applications and provides insights for further optimization of MOF‐based energy storage materials.