Trace ruthenium enables synergistic interactions in NiFeB nanosheets for industrial-current-density water oxidation

The oxygen evolution reaction (OER) represents the dominant kinetic bottleneck in electrochemical water splitting, thereby imposing stringent demands on the development of advanced electrocatalysts that simultaneously deliver high activity and long-term stability under industrial operating conditions for large-scale hydrogen production. Here, we report the rational design and fabrication of a hierarchical Ru-decorated NiFeB nanosheet architecture (Ru@NiFeB), constructed via sequential electrodeposition and hydrothermal processing on three-dimensional nickel foam substrate. The strategic incorporation of trace Ru species (~2 wt.%) drives pronounced electronic modulation at the heterointerface, thereby fundamentally regulating the adsorption energetics of oxygen-containing intermediates. The resulting Ru@NiFeB electrode exhibits state-of-the-art OER performance, with an overpotential of merely 235 mV at 100 mA/cm² in 1 mol/L KOH, surpassing the activity of commercial RuO₂ catalysts. Remarkably, the electrode sustains a current density of 1000 mA/cm² for over 150 h in a concentrated 4 mol/L KOH electrolyte without discernible degradation, thereby establishing one of the most stable low-doped noble metal-based OER catalysts reported to date. This work establishes a viable pathway toward cost-effective and robust electrocatalysts for industrial alkaline water electrolysis, thereby substantially advancing the feasibility of large-scale green hydrogen production.