Development of Robust Dual-Functional NiX (X: Fe, TiO2) Electrocatalysts via Atmospheric Plasma Spray for Efficient Water Splitting Applications

Abstract

As traditional energy resources become scarcer, the need for cleaner and more efficient energy carriers becomes increasingly urgent. In response to this challenge, hydrogen energy has gained attention as a practical and clean alternative with its potential for zero emissions and ability to be generated through renewable processes. Water splitting is essential for sustainable energy production as it generates hydrogen, a clean fuel, and oxygen through electrochemical reactions. In this study, we fabricated robust dual-functional nickel-based NiX (X: Fe, TiO2) electrocatalysts, using atmospheric plasma spray (APS) for water splitting. The nickel-based electrocatalysts demonstrated excellent catalytic activity for both the oxygen evolution reaction (OER) and the hydrogen evolution reaction (HER). Specifically, the NiX electrocatalyst exhibited a remarkable OER performance with an overpotential of 209 mV at a current density of 50 mA cm-2 and a Tafel value of 173.54 mV/Dec. For HER, it exhibited the overpotential of 298 mV at 20 mA cm-2 with a Tafel value of 85.86 mV/Dec, making NiFe particularly efficient in achieving high current densities with minimal energy input. NiTiO2 electrocatalyst exhibits stability in acidic conditions, making it suitable for long-term applications. The surface morphology and wettability of the materials were assessed before and after electrochemical reactions. Overall, this study highlights the single-step fabrication process of highly stable and efficient dual-functional electrocatalysts for water splitting.