Synthesis and electrochemical characterisation of MXene/Cu-MOF nanocomposites for energy storage applications

This research reports on the fabrication and electrochemical characterisation of a new nanocomposite Cu-MOF/MXene for supercapacitor applications. The composite was synthesised through a hydrothermal method involving Ti₃C₂ MXene and a copper-based metal-organic framework (Cu-MOF). X-ray diffraction (XRD) demonstrated formation of the two constituents and high crystallinity, while scanning electron microscopy (SEM) showed dispersal Cu-MOF microcrystals measuring 300–700 nm in size over MXene sheets of size 500-1000 nm. FTIR and photoluminescence (PL) spectroscopy proved strong interfacial interactions, confirming that the composite exhibited an emission peak at 561 nm with a band gap of 2.21 eV. Tauc analysis showed clear optical properties in the visible detection range, and thus Zeta potential showed a surface charge of -18.9 mV which ensures good colloidal stability. Electrochemical impedance spectroscopy (EIS) values demonstrated a charge transfer resistance of 120 Ω and an apparent electron transfer rate of 3.17×10⁻² cm/s. Cyclic voltammetry (CV) confirmed a high specific capacitance of 400 F/g at 5 mV/s and GCD analysis showed a value of 187.5 F/g for 1.0 A/g. The material showed retaining approximately70% of the initial capacitance after 5000 cycles, confirming the superb long-term stability. These results confirm the synergistic development of the MXene/Cu-MOF composite, making it a strong candidate for high-performance energy storage devices.