Surface Reconstruction of FeNi₂Se₄ for Highly Selective and Stable Seawater Electrolysis

Seawater electrolysis serves as a promising way for large-scale green hydrogen production. However, the anode faces challenges related to selectivity and severe corrosion by Cl– during oxygen evolution. Herein, we propose a reconstruction strategy for FeNi2Se4 to enhance the catalytic activity, oxygen evolution selectivity, and durability of seawater electrolysis. The high-valence NiFeOOH formed during the reconstruction process of FeNi2Se4 acts as the active center for efficient catalysis. Meanwhile, the dissolution of Se transforms into SeOx covering the NiFeOOH, which protects the active species from Cl– corrosion by electrostatic repulsion. The catalyst exhibits 220 and 320 mV overpotentials to achieve 10 and 200 mA cm-2, respectively, while sustaining 100% OER selectivity for the OER and demonstrating long-term stability.