Hydrogen Evolution Reaction in Acidic, Neutral and Seawater Electrolyte Using Bimetallic Cu@Pd Core‐Shell Nanostructures

Abstract For the manifestation of hydrogen fuel cells, hydrogen availability at low cost is an essential requirement. Hydrogen evolution reaction (HER) during electrochemical water splitting is anticipated to produce green hydrogen commercially. Alternative electrocatalysts to the Pt based materials have shown low performance in terms of high overpotential or low cycle life. To meet the high demand for minimal usage of noble metals toward HER, bimetallic and/or core‐shell nanostructures are being evaluated. The present report demonstrates a facile preparation of Cu@Pd core‐shell nanostructures over a copper foil toward HER, involving a template electrodeposition of copper followed by palladium deposition through galvanic replacement reaction. The results show highly promising catalytic stability toward HER in acidic medium with an overpotential value of 185 mV for reaching a current density of –10 mA.cm −2 , together with a Tafel slope of 120 mV.dec −1 , which suggests a facile HER kinetics over Cu@Pd/Cu foil and a promising long‐term stability for 16 h suggesting their potentiality toward commercial HER applications. The catalysts are further extended toward HER in neutral and seawater electrolytes to evaluate the versatility of Cu@Pd/Cu foil. The HER activities are supported by in situ Raman analysis to get interfacial information during the reaction.