Molecular-Level Pore\nTuning in 2D Conductive Metal–Organic\nFrameworks for Advanced Supercapacitor Performance

Two-dimensional (2D) electrically conductive metal–organic\nframeworks (MOFs) have emerged as viable candidates for active electrode\nmaterials in supercapacitors due to their high electrical conductivity,\nhigh specific surface area, and intrinsic redox-active sites. Despite\ntheir promising electrochemical performance, their pseudocapacitive\nbehavior via fast and reversible charge transfer reactions remains\nyet to be fully exploited. Here, we investigate the electrochemical\nenergy storage mechanism of Cu<sub>3</sub>(HHTATP)<sub>2</sub> (HHTATP\n= 2,3,6,7,10,11-hexahydroxy-1,5,9-triaminotriphenylene), a 2D conductive\nMOF featuring characteristic redox-active pendant aromatic amines.\nCu<sub>3</sub>(HHTATP)<sub>2</sub> exhibited pseudocapacitive charge\nstorage with an average gravimetric capacitance of 340 ± 15 F\ng<sup>–1</sup> at a discharge rate of 0.2 A g<sup>–1</sup> and maintained a capacitance retention over 90% after 7000 galvanostatic\ncycles at 5 A g<sup>–1</sup>. The polar pendant amines not\nonly enhanced capacitance via additional amine/imine redox activity\nbut also reduced interfacial charge transfer resistance through modified\nelectrode–electrolyte interactions. These results highlight\nthe potential of molecular-level pore environment tuning as a strategic\napproach in materials design for energy storage applications.