Multi-component NiO–Fe₂O₃–CuO anchored on MXene as supercapacitor electrode material

Abstract

In this study, a novel ternary composite of NiO–Fe₂O₃–CuO was successfully synthesized and anchored on MXene (Ti₃C₂) nanosheets via a facile hydrothermal method, using nickel foam as the current collector. The resulting NiO–Fe₂O₃–CuO/MXene composite was thoroughly characterized by XRD, FESEM, and elemental mapping analyses, confirming the coexistence and homogeneous distribution of all constituent phases. Electrochemical evaluations in 2 M KOH electrolyte revealed that the NiO–Fe₂O₃–CuO/MXene electrode exhibits outstanding faradaic activity and enhanced charge storage, as evidenced by its large integrated CV area, pronounced redox peaks, and the highest specific capacitance of 790 F g⁻¹ at 1 A g⁻¹. The composite also demonstrated remarkable rate capability, retaining 74.6% of its capacitance at 4 A g⁻¹, as well as superior cycling stability (91.5% retention after 5000 cycles) compared to NiO–Fe₂O₃–CuO and MXene electrodes. This performance enhancement is attributed to the synergistic effects between the multi-metal oxides and the conductive MXene scaffold, which offers abundant electroactive sites, rapid ion/electron transport, and robust structural integrity. These findings suggest that the NiO–Fe₂O₃–CuO/MXene hybrid is a highly promising electrode material for next-generation high-performance supercapacitors.