Exploring the influence of precursor concentration on hydrothermally synthesized rGO/MnFe2O4 composite for a high-performance supercapacitor

This study uses a scalable hydrothermal method to synthesize GO-Fe and rGO/MnFe2O4 composites. Mn precursor variation during the synthesis to look at its effect on overall properties and application is carried out, which was not done before. From XRD, the phase and their crystal structure of GO-Fe and GMF are confirmed. The FT-IR and Raman studies are used to identify the stretching-bending vibrations and the presence of functional groups in GO-Fe and GMF. With an increase in the Mn concentration, the modulation in the morphology of GMF composite is evident, progressing from spherical to cuboidal structures. Furthermore, TEM and XPS provide a deeper understanding of the morphological and electronic states of the GMF3 composite. The GMF3 electrode exhibits a high specific capacitance of 1380.1 F/g in 1 M KOH electrolyte at 2 mA/cm2 and long cycling stability (92.5% after 10,000 cycles at 10 mA/cm2). Additionally, the GMF3//GMF3 solid supercapacitor device demonstrated a maximum specific capacitance of 79.33 F/g with an energy density of 11.01 Wh/kg and a power density of 583.33 W/kg at 7 mA/cm2, while retaining 88.67% of its capacitive performance over 2000 cycles. Overall findings suggest how the electrochemical activities of GO-Fe and GMF composites are changed by the synergistic impact of Mn concentration and GO composite.