PtNi Nanowires Coated with Amorphous FeO_x Enable Robust Alkaline Seawater Hydrogen Evolution

Promoting water dissociation kinetics while overcoming the severe chloride-induced degradation of platinum (Pt)-based catalysts is critical for practical seawater hydrogen evolution, yet remain significant challenges. Herein, we report amorphous FeOx- coated PtNi nanowires (NWs) (PtNi@FeOx) featuring an atomic-scale amorphous shell-crystalline core heterointerface, which deliver outstanding alkaline seawater electrolysis performance. The PtNi@FeOx catalyst surpasses conventional Pt-based materials, demonstrates overpotentials as low as 30 mV (10 mA cm - 2) and 81 mV (100 mA cm - 2), and exhibits excellent endurance of 100 h at 100 mA cm - 2. Theory of density functional calculations reveal that the synergistic amorphous/crystalline heterointerface accelerates water splitting kinetics while modulating hydrogen adsorption energetics at active centers, thereby reducing the reaction energy landscape. Moreover, the ultrathin amorphous FeOx layer selectively facilitates H intermediate adsorption while effectively repelling chloride ions, thus significantly enhancing catalyst stability under complex seawater conditions. This work provides a promising atomically interface-engineering strategy for designing electrocatalyst toward highly efficient and robust large-scale seawater electrolysis.