Spinel MnFe2O4 nanoparticles with improved surface area and charge transfer characteristics for next-generation supercapacitors

Abstract

The growing demand for sustainable and efficient energy storage devices has accelerated the development of advanced electrode materials for high-performance supercapacitors. In this work, MnFe₂O₄ nanoparticles were successfully synthesized through a novel green co-precipitation approach using Curcuma longa extract as a natural reducing and stabilizing agent. XRD analysis confirmed the formation of highly crystalline spinel MnFe₂O₄ with an average crystallite size of 19.9 nm and excellent phase purity. Raman spectroscopy further validated the characteristic vibrational modes of the spinel ferrite structure, while BET analysis revealed an enhanced surface area with mesoporous characteristics favorable for ion diffusion. SEM images demonstrated porous cauliflower-like interconnected morphology, and EDX confirmed the homogeneous distribution of Mn, Fe, and O elements without impurities. Electrochemical studies exhibited remarkable pseudocapacitive behavior with a high specific capacitance of 295 F g⁻¹ at 0.8 A g⁻¹ and 87.3% capacitance retention after 5000 charge–discharge cycles. Furthermore, EIS analysis revealed low charge transfer resistance and enhanced ion diffusion kinetics, confirming the strong potential of green-synthesized MnFe₂O₄ for sustainable next-generation supercapacitor applications. Explanation: Green-synthesized MnFe2O4 nanoparticles exhibit a porous, interconnected structure and a specific capacitance of 295 F g−1, demonstrating their potential as sustainable supercapacitor electrode materials. Explanation: Green-synthesized MnFe2O4 nanoparticles exhibit a porous, interconnected structure and a specific capacitance of 295 F g−1, demonstrating their potential as sustainable supercapacitor electrode materials. MnFe2O4 nanoparticles were successfully synthesized via a green co-precipitation route using Curcuma longa extract. The porous, interconnected morphology and enhanced surface characteristics promoted efficient ion diffusion and charge transport. The MnFe2O4 electrode delivered a high specific capacitance of 295 F g⁻¹ at 0.8 A g⁻¹. The charge-transfer resistance decreased from 3.19 Ω to 2.76 Ω after cycling. The retaintivity 87.3% of its capacitance after 5000 charge–discharge cycles, demonstrating good cycling stability. MnFe2O4 nanoparticles were successfully synthesized via a green co-precipitation route using Curcuma longa extract. The porous, interconnected morphology and enhanced surface characteristics promoted efficient ion diffusion and charge transport. The MnFe2O4 electrode delivered a high specific capacitance of 295 F g⁻¹ at 0.8 A g⁻¹. The charge-transfer resistance decreased from 3.19 Ω to 2.76 Ω after cycling. The retaintivity 87.3% of its capacitance after 5000 charge–discharge cycles, demonstrating good cycling stability.