Amino-functionalized Zr-MOFs with ferrocene linkages for high-energy, long-life hybrid supercapacitors

The development of next-generation supercapacitors depends on enhancing the electrical conductivity and redox activity of metal-organic frameworks (MOFs). In this study, an assisted solvothermal technique was used to produce UiO-66-NH₂, an amino-functionalized zirconium-based MOF. Ferrocene groups were then added via post-synthetic functionalization, yielding UiO-66-NH₂-Fc. High crystallinity, well-defined porosity, and the effective integration of ferrocene moieties through Schiff-base condensation were validated by structural characterization using XRD, FTIR, BET, Raman, FESEM-EDS, TEM, and related techniques. The resultant UiO-66-NH₂-Fc promoted effective ion transport with a uniform shape having a large BET surface area of 773.03 m² g^-1. At 1 A g^-1 in 2 M KOH, the specific capacitance (C _sp) was much greater, 345.16 F g^-1, as found by electrochemical tests, more than twice that of pure UiO-66-NH₂ (164.07 F g^-1). At a power density (P _d) of 0.99 kW kg^-1, the device delivered an energy density of 5.96 Wh kg^-1 when built in an asymmetric two-electrode arrangement. The conductive Zr-MOF framework and redox-active ferrocene cores work in conjunction to provide these enhancements. As a hybrid pseudocapacitive material that can bridge faradaic and electric-double-layer storage mechanisms for high-performance supercapacitors, UiO-66-NH₂-Fc shows great overall potential.