Turning Degradation into Opportunity: Rapid Regeneration of FeNi-Based Amorphous Alloy Enabling Sustainable High-Current-Density Oxygen Evolution

Developing electrocatalysts with high stability under industrial current densities is crucial for practical water electrolysis toward green hydrogen production yet remains a formidable challenge. Here, Fe40Ni38Mo4B18 amorphous alloy ribbons are fabricated via a scalable single-roller melt-spinning method and used as self-supported oxygen evolution electrodes. The as-prepared amorphous alloy sustains continuous operation at 500 mA cm–2 for 730 h before noticeable deactivation. Mechanistic investigations reveal that under high-current anodic conditions, surface reconstruction accompanied by Fe dissolution leads to the formation and accumulation of a Fe-depleted, Ni-rich (oxy)hydroxide passivation layer, resulting in reduced Ni–Fe synergistic sites and limited charge transfer. Based on this understanding, a rapid regeneration strategy is developed to remove the inactive surface layer and induce structural reconfiguration. The regenerated electrode exhibits reduced overpotential at 10 mA cm–2 (from 304 to 243 mV) and sustains an additional 710 h of operation at 500 mA cm–2 at a lower applied potential. These results indicate that catalyst deactivation and regeneration are governed by surface chemical evolution and provide insight into extending catalyst lifetime under practical operating conditions.