Sulfur-Doped Nickel Ferrite for Green Hydrogen at High Current Density.

Abstract

The primary obstacle in electrolyzing water is that prolonged large-current operation quickly degrades performance, making it difficult to achieve efficient and continuous hydrogen evolution at high current densities. This work prepared sulfur-doped nickel ferrite nanocomposites using the simple hydrothermal method to improve electrocatalytic green hydrogen production at high-current densities. X-ray diffraction (XRD), scanning electron microscopy (SEM), and X-ray photoelectron spectroscopy (XPS) were used to analyze the crystalline structure, morphology, and chemical composition of the synthesized nanocomposites. The prepared S-NiFe2O4/NF (NS-85/NF) catalyst exhibits excellent electrochemical water-splitting activity, a low overpotential, a high current density, and extended stability lasting more than 12 hours. The NS-85/NF electrode has a cathodic current density of 300 mA cm-2 at -0.329 V overpotential and at the lowest overpotential of -0.264 V, the electrode has a current density of 100 mA cm-2. Our work provides new approaches to developing earth-abundant, stable, scalable, and highly effective catalysts for high-current density water electrolysis.