Scalable one-pot synthesis of amorphous iron-nickel-boride bifunctional electrocatalysts for enhanced alkaline water electrolysis

Abstract

Green hydrogen is considered an attractive energy vector that can easily replace fossil fuel consumption, meeting global energy demands. Therefore, developing easily scalable, efficient and cost-effective electrocatalysts for water electrolysis is imperative for our transition to a more sustainable energy future. To this end, we demonstrate here a simple and scalable one-pot chemical reduction method for the synthesis of amorphous iron nickel boride nanoparticles with a spherical morphology. The iron to nickel ratio was easily adjusted during synthesis, and how it effects electrocatalytic performance was evaluated. The electrocatalyst powder with the highest concentration of metallic iron, or iron bonded to nickel, exhibited enhanced bifunctional OER and HER electrocatalytic activity, outperforming RuO₂, the current state-of-the-art electrocatalyst; reaching industrial current densities, with an OER overpotential of 252 mV at 10 mA cm⁻² and 349 mV at 100 mA cm⁻². In our view, this work delivers an important method for the scalable synthesis of amorphous bimetallic boride nanoparticles with adjustable electronic structure for achieving enhanced water electrolysis at a minimum cost.