Ruthenium Cobalt Nanoalloy Derived from Its Prussian Blue Analogue (RuCo‐PBA) for Efficient Hydrogen Evolution Electrocatalysis

Abstract Prussian blue analogue (PBA)‐derived electrocatalysts have attracted significant interests for energy conversion applications. They have been extensively used for the production of renewable energy carriers like hydrogen in order to replace platinum based precious materials. We introduced a ruthenium cobalt PBA‐derived bimetallic RuCo nano‐alloy with the presence of the N ‐doped graphitised carbon (RuCoNA/AB@T, where T  = 500–800 °C), following high temperature annealing in inert atmosphere. By varying the temperature (from 500 to 800 °C) during the annealing process, series of ruthenium cobalt nano‐alloy products were obtained: RuCoNA/AB@500, RuCoNA/AB@600, RuCoNA/AB@700, and RuCoNA/AB@800 at 500, 600, 700, and 800 °C temperature, respectively. Temperature variation had a very important role in optimizing the activity of the electrocatalyst toward hydrogen evolution reaction (HER). Amongst different high‐temperature annealed products, RuCoNA/AB@600 shows superior electrocatalytic performance due to its distinctive granule like morphology, lower overpotential value, smaller Tafel slope (122 mV/dec), smaller charge transfer resistance (18.69 Ω), and larger electrochemically active surface area (7.09 cm 2 ) that provides a large number of electrochemically active sites. RuCoNA/AB@600 exhibits a lower overpotential of 129 mV to deliver 10 mA cm −2 current density. Furthermore, 96 h of long‐term stability of the electrocatalyst reflected its practical applicability.