Anion Shielding in Nb‐WO 3 /WS 2 Heterostructures: A Strategy for Efficient and Corrosion‐Resistant Seawater Electrolysis

Abstract Seawater electrolysis is a promising route for sustainable hydrogen production, but chloride‐induced corrosion severely limits its practicality. Here, a dual‐modulated Nb‐WO 3 /WS 2 heterostructure electrocatalyst that simultaneously enhances oxygen evolution reaction (OER) kinetics and resists chloride corrosion is designed. The Nb‐WO 3 /WS 2 anode achieves remarkably low overpotentials of 212 and 369 mV at 10 and 100 mA cm −2 , respectively, in alkaline simulated seawater, with a Tafel slope of 35.58 mV dec −1 . The catalyst also exhibits remarkable stability, maintaining performance over 1000 CV cycles. Mechanistic studies reveal that Nb doping introduces oxygen vacancies and modulates the electronic structure, while the in situ formation of a WO x protective layer during OER effectively repels Cl − via anion shielding. This work provides a strategic approach to developing durable, efficient, and non‐precious‐metal‐based catalysts for seawater splitting.