Hollow Chevrel‐Phase NiMo₃S₄ for Hydrogen Evolution in Alkaline Electrolytes

Electrochemical water splitting to generate molecular hydrogen requires catalysts that are cheap, active, and stable, particularly for alkaline electrolyzers, where the cathodic hydrogen evolution reaction is slower in base than in acid even on platinum. Herein, we describe the synthesis of new hollow Chevrel‐phase NiMo 3 S 4 and its alkaline hydrogen evolution reaction (HER) performance: onset potential of −59 mV, Tafel slope of 98 mV per decade, and exchange current density of 3.9×10 −2 mA cm −2 . This Chevrel‐phase chalcogenide also demonstrates outstanding long‐term stability under harsh HER cycling conditions. Chevrel‐phase nanomaterials show promise as efficient, low‐cost catalysts for alkaline electrolyzers.