Elevating electrochemical performance of MnFe2O4@g-C3N4 nanohybrid for energy storage devices

•Hydrothermal technique was used to synthesized MnFe2O4, g-CN and MnFe2O4@g-CN hybrid.•MnFe2O4@g-CN hybrid exhibit energy density (44.87 Wh kg−1) and power density (239 W kg−1)•MnFe2O4@g-CN hybrid revealed high stability after 5000th cycles.•MnFe2O4@g-CN hybrid exhibit low Rct value of 0.08 Ω. Numerous researchers are investigating sustainable and efficient energy-generating and storing methods in response to the depletion of fossil fuels. Supercapacitor (SCs) are now important due to their advanced energy storage and conversion technology. In present work hydrothermal route was employed to synthesize MnFe2O4, g-C3N4 and MnFe2O4@g-C3N4 nanohybrid materials to study electrochemical performance. The MnFe2O4@g-C3N4 nanohybrid demonstrated specific capacitance (Cs) of 1414F/g at 1 A/g and exceptional durability after 5000th cycle with small charge transfer impedance (Rct = 0.08 Ω) determined from Nyquist plot which indicates its promising performance toward supercapacitor application. Furthermore, a symmetric two-electrode test of MnFe2O4@g-C3N4 nanohybrid performed and exhibited Cs of 392.02F/g at 1 A/g that can be ascribed to robust interfacial interaction between g-C3N4 and MnFe2O4. The findings indicate a novel approach to manufacturing g-C3N4 using spinel oxide materials for supercapacitor devices.