In Situ Engineering of Strongly Coupled RuO₂-MoO₃ Heterointerface for Ultra-Stable Bifunctional Electrocatalysis...

Ruthenium (Ru)-based materials are promising catalysts for alkaline water electrolysis; however, their practical application is severely limited by insufficient activity and poor stability. To address these challenges, we proposed an in situ gas-phase transformation strategy that constructs strongly coupled heterointerfaces with atomic-scale intimate contact, yielding the RuO₂-MoO₃/CC catalyst. Owing to the robust interface structure, the catalyst drives the hydrogen evolution reaction (HER) with overpotentials of 44 mV in alkaline water and 46 mV in alkaline seawater at 10 mA cm^{- 2}, and the oxygen evolution reaction (OER) with 195 mV and 201 mV, respectively. Moreover, it delivers outstanding operational stability exceeding 200 h in both electrolytes. Experimental and theoretical calculations indicate that strong electronic interactions induce directional charge transfer on the heterointerfaces, which modulates the electron cloud density of active sites, optimizes the adsorption of reaction intermediates, and reinforces structural stability. Consequently, this work not only demonstrates a high-performance, corrosion-resistant electrocatalyst but also provides a new materials design strategy and theoretical basis for engineering strong interfacial interactions.