Investigating the Electrocatalytic Oxygen Evolution Reaction of Hydrothermally Synthesized NiFe2O4 Nanoparticles

Abstract

In this study, nickel ferrite (NiFe2O4) nanoparticles were synthesized using the hydrothermal method at various pH values. The objective was to investigate the influence of pH variation on particle size and electrocatalytic activity. The formation of cubic phase nanoparticles was confirmed through X-ray diffraction (XRD) analysis. To characterize the electrochemical properties, the nickel ferrite nanoparticles were coated onto a stainless steel substrate using the doctor blade technique. The microstructural analysis was conducted using scanning electron microscopy (SEM). The samples were further analyzed using linear sweep voltammetry (LSV) and electrochemical impedance spectroscopy (EIS). The average crystallite size, determined from the XRD pattern, was approximately 40 nm. SEM images revealed a conversion from nanoplates to a granular morphology. The synthesized electrode exhibited an overpotential of 392 mV at 10 mA/cm2 and demonstrated good stability for 5 hours. These findings highlight the excellent electrocatalytic activity of nickel ferrite nanoparticles for the oxygen evolution reaction (OER).