Synergistic interfaces in a MoC-Ni<sub>4</sub>Mo-Ni<sub>2</sub>P heterostructure drive durable bifunctional electrocatalysis for industrial water splitting.

Abstract

The development of electrocatalysts capable of stable operation at industrial current densities is critical for practical green hydrogen production. In this study, a MoC-Ni₄Mo-Ni₂P heterostructure fabricated on stainless steel mesh demonstrates exceptional bifunctional activity and stability in alkaline media. The conductive MoC and Ni₄Mo synergistically lower the interfacial charge transfer resistance and accelerate the reaction kinetics. Meanwhile, the Ni₂P interface effectively reduces the energy barrier for critical reaction intermediates. This catalyst demonstrates low overpotentials of 277.6 mV for HER and 347.2 mV for OER at 2000 mA cm^-2 in 1.0 M KOH, and it can operate stably for 100 h at 1000 mA cm^-2. In a symmetric electrolyzer, it requires only 1.659 V to reach 1000 mA cm^-2 with robust performance also demonstrated in alkaline seawater and concentrated KOH at elevated temperatures. This study offers a practical design strategy for industrial electrocatalysts under high current density.