PtNi Nanorods Catalysts Prepared by Magnetron Sputtering for Alkaline Hydrogen Evolution Reaction

Abstract

The development of cost-effective and highly efficient catalysts for the hydrogen evolution reaction (HER), particularly in alkaline environments, is a critical challenge for hydrogen applications. One promising approach involves the alloying of noble metals with transition metals. This study presents the synthesis of PtNi nanorod catalysts, characterized by a thickness of 500 nm, which were fabricated via magnetron sputtering onto nickel foam. When evaluated in a 1 M KOH electrolyte, the Pt–Ni alloy demonstrates superior HER performance compared with both Ni and Pt, exhibiting an overpotential of 35 mV at 10 mA/cm² and a Tafel slope of 29 mV/dec. The enhanced catalytic activity is attributed to several factors, including a high electrochemically active surface area, increased mass activity, elevated turnover frequency, and reduced electrochemical impedance. Furthermore, the Pt–Ni catalyst maintains remarkable stability at a current density of 10 mA/cm² over a duration of 100 h. The improved HER performance is ascribed to the nanorod architecture, which features a high density of grain boundaries, as well as the synergistic interactions between Ni and Pt.