Galvanostatically Deposited PtNi Thin‐Films as Electrocatalysts for the Hydrogen Evolution Reaction

The synthesis of hybrid platinum materials is fundamental to enable alkaline water electrolysis for cost‐effective H(2) generation. In this work, we have used a galvanostatic method to co‐deposit PtNi films onto polycrystalline gold. The surface concentrations of Ni (Γ(Ni)) and Pt (Γ(Pt)) were calculated from electrochemical measurements; the Γ(Pt)/Γ(Ni) ratio and electrocatalytic activity of these materials towards hydrogen evolution reaction (HER) in 1 M KOH show a strong dependence on the current density pulse applied during the electrodeposition. Analysis of the Tafel parameters hints that, on these deposits, HER proceeds through a Volmer‐Heyrovsky mechanism. The galvanostatically deposited PtNi layers present a high current output per Pt gram, 3199 A g(Pt) (−1), which is significantly larger compared to other PtNi‐based materials obtained by more extended and more complex synthesis methods.