Orchestrating a Supercapacitive Symphony: Copper–Metal Organic Framework Integrated MXene Nanosheets on Graphite Sheet Electrodes Unveiling Its Synergistic Interactions by Density Functional Theory Study

This study reports the successful synthesis of a Cu-based metal–organic framework (Cu MOF) integrated with delaminated titanium carbide MXene (D-MXene) to form a composite electrode material (Cu MOF/D-MXene) for high-performance supercapacitors at the graphite sheet (GS) electrode. The Cu MOF/D-MXene composite was fabricated using a simple solution-based approach and exhibited a remarkably high surface area of 933 m2 g–1. This exceptional surface area and the synergistic interaction between the Cu MOF and D-MXene resulted in an outstanding electrochemical performance. The Cu MOF/D-MXene electrode delivered a specific capacitance of 3249.92 F g–1 at a current density of 1 A g–1 in a three-electrode system with a 6 M KOH electrolyte. Density functional theory calculations supported the strong interfacial interaction between Cu MOF and D-MXene, with a calculated binding energy of −9.56 eV. Furthermore, an asymmetric supercapacitor device was constructed by using Cu MOF/D-MXene as the cathode and activated carbon as the anode. This device achieved a specific capacitance of 746.53 F g–1 at 1 A g–1 within a potential window of 1.5 V. Moreover, this study demonstrates excellent stability, retaining 95% of its initial capacitance after 10,000 cycles at a high current density of 15 A g–1. These findings highlight the potential of Cu MOF/D-MXene composites as promising electrode materials for next-generation supercapacitors with exceptional energy storage capabilities and long-term cycling stability.