Boosting the Capacitive Property of Ni Doped α-Fe2O3 Via Incremental Substitution of Mn for High Performance Supercapacitor

Abstract

To address energy crises via expertly designing supercapacitors, researchers considered transition metal oxides as possible options due to their outstanding capacitive capabilities. A sophisticated approach has been adopted to tailor their characteristics by incorporating 3d ions into their structures. Here, we synthesized pure Fe2O3 and Ni1-xMnxFeO3(x=0,0.3,0.5,0.7,1) via simple hydrothermal method and investigated the impact of gradually substituting of Mn on the structural, electronic, and electrochemical properties of iron oxide (Fe2O3). The XRD and Raman confirmed the single-phase Hematite's rhombohedral crystal structure. SEM analysis demonstrated a change in the morphology of nanostructures, transitioning from spherical- to nano-rod structures. Thorough investigations into the electrochemical properties of the synthesized Ni1-xMnxFeO3 nanoparticles showcased distinctive traits resembling battery-type materials with super capacitive performance. Notably, comprehensive cyclic voltammetry (CV) and Galvanostatic Charge Discharge (GCD) examinations unveiled that the Ni1-xMnxFeO3 nanoparticles exhibited an escalation in specific capacitance from 633 F/g to 1251 F/g with higher Mn content. This increase culminated in the highest specific capacitance of 1,251 F/g for MnFeO3 nanoparticles under the current density of 1 A/g. This achievement was with remarkable charge retention (96%), while electrochemical impedance spectroscopy (EIS) demonstrated a notably conductive nature. The noteworthy capacitance and robust stability of the MnFeO3 nanorods suggest their potential suitability as candidates for supercapacitors.