Hydroxyapatite-Supported Nickel(0) Nanoparticles: A Cost-Effective and Efficient Electrocatalyst for Oxygen Evolution Reaction in Alkaline Media

Abstract Water splitting for hydrogen production is a crucial technology for sustainable energy alternatives. The oxygen evolution process (OER) poses a considerable problem owing to its sluggish kinetics. This study examines the electrocatalytic characteristics of hydroxyapatite-supported nickel nanoparticles (Ni/HAp) as a promising catalyst for OER in alkaline environments. Ni/HAp nanoparticles were made via a straightforward impregnation-reduction procedure, and their structural and electrochemical characteristics are analyzed using a combination of analytical techniques including X-ray diffraction, field-effect scanning electron microscopy, transmission electron microscopy, X-ray photoelectron spectroscopy, and electrochemical methods. The Ni/HAp electrocatalyst exhibits an onset potential of 1.61 V (vs. RHE), an overpotential of 521 mV at a current density of 5 mAcm-2, and a Tafel slope of 148.9 mVdec-1 in a 1.0 M KOH solution. The high turnover frequency (0.747 s-1 at 350 mV) and double-layer capacitance (0.0208 mFcm-2) indicate the material's potential for catalytic activity. The results suggest that Ni/HAp is a promising and cost-effective electrocatalyst for the OER.