Copper ferrite decorated multi walled carbon nanotubes: A synergistic nanohybrid for dual-functionality in asymmetric supercapacitors and oxygen evolution catalysis

Transition metal oxides have long been recognized as promising electroactive materials for energy storage and conversion owing to their rich redox chemistry and structural robustness. However, limited conductivity and poor cycling-stability often hinder performance. To address this, a CuFe 2 O 4 decorated multi-walled carbon nanotube (MWCNT)(1 wt%) nanocomposite was developed using a simple hydrothermal strategy. The hHybrid structure effectively couples the superior electrochemical activity of CuFe 2 O 4 with the high conductivity and mechanical stability of MWCNTs, leading to a multifunctional electrode system. The CuFe 2 O 4 @MWCNT nanocomposite demonstrates exceptional electrochemical performance, delivering a high specific capacitance of 815.7 F g⁻¹ at 1 A g⁻¹ and cycling stability, retaining 91.1% after 10,000 charge-discharge cycles at 20 A g⁻¹. When assembled into an asymmetric supercapacitor device, it achieves an impressive energy density of 52.4 Wh kg⁻¹ at a power density of 799 W kg⁻¹, reflecting a strong balance between energy and power output. Beyond supercapacitive behaviour, the composite also shows efficient OER activity toward the oxygen evolution reaction, achieving a 300 mV overpotential at 10 mA cm⁻² with a Tafel slope of 66 mV dec⁻¹ and high stability. These results highlight in the synergistic effect between CuFe 2 O 4 and MWCNTs, offering an efficient, scalable, earth-abundant material for next-generation energy storage and conversion technologies