Engineered Antiperovsksite Nitride for Boosting Electrocatalytic Green Hydrogen Production

Abstract Developing efficient and robust electrocatalysts for overall water splitting is vital for sustainable green hydrogen production, yet it remains a formidable challenge. In this work, a robust Mo-doped FeNNi3 antiperovskite catalyst (Mo-FeNNi3) is fabricated via a facile two-step strategy involving hydrothermal reaction and subsequent nitrogen treatment. The designed hydrangea-like structure not only endows the electrocatalyst with a robust framework but also exposes abundant available active sites, thereby facilitating efficient mass transport and accelerating reaction kinetics. The as-prepared Mo-FeNNi3 electrocatalyst delivers exceptional catalytic performance, requiring very low overpotentials of 17, 36, and 77 mV to achieve a current density of 10 mA cm–2 for the hydrogen evolution reaction in alkaline, acidic, and neutral media, respectively, alongside an outstanding oxygen evolution reaction overpotential of 223 mV in alkaline solution. Remarkably, when employed in an alkaline electrolyzer (Mo-FeNNi3||Mo-FeNNi3), it delivers a current density of 10 mA cm–2 at a remarkably low cell voltage of 1.472 V, significantly outperforming the commercial RuO2||Pt/C benchmark (1.536 V). The theoretical studies provide evidence that the electronic structure regulation in Mo-FeNNi3 accelerates water dissociation kinetics and optimizes the adsorption/desorption energies of reaction intermediates, thereby dramatically enhancing the hydrogen production efficiency.