Optimized rGO/NiCoFe₂O₄ nanocomposites synthesized via sol-gel auto-combustion for supercapacitor applications

This investigation presents the synthesis of composition-tuned rGO/NiCoFe₂O₄ nanocomposites via a modified Hummers' method and sol-gel auto-combustion approach. The Ni content was systematically varied to investigate its influence on structural, morphological, and electrochemical properties. XRD confirmed the formation of a spinel NiCoFe₂O₄ phase, while FTIR and FESEM revealed strong interfacial interaction and a porous interconnected morphology. Electrochemical analysis in 3 M KOH demonstrated that the optimized RNC80 sample exhibits a high specific capacitance of 275 F g^-1 (from GCD) and 250 F g^-1 (from CV), along with low charge transfer resistance (72.5 Ω). The enhanced performance is attributed to the synergistic effect between conductive rGO and redox-active NiCoFe₂O₄, facilitating efficient ion diffusion and electron transport. These results highlight the potential of composition-engineered rGO/ferrite nanocomposites for advanced supercapacitor applications.