Synergistic coupling of core-shell Ru@RuO₂ with in-situ incorporated electronegative nitrogen for enhanced bifunctional water electrolysis

Combining the precise incorporation of electronegative nitrogen (N) species with a core-shell structure is essential for achieving high-performance bifunctional electrocatalysis. In this study, we leverage the intrinsic catalytic properties of ruthenium (Ru) to propose a method that simultaneously achieves in-situ controllable N doping and anchoring of Ru. Subsequently, a core-shell structured Ru@RuO₂/NC electrocatalyst is obtained via air oxidation. Experimental and theoretical results reveal that the Ru@RuO₂ induces strong metal-oxide interfacial coupling, while the introduction of N promotes the redistribution of charges in the material. The synergistic effect not only endows the material with bifunctional properties but also enhances its intrinsic activity and significantly improves the utilization efficiency of Ru (4.2 wt%). Ru@RuO₂/NC exhibits outstanding bifunctional activity for oxygen evolution (223 mV@10 mA cm^-²) and hydrogen evolution (39 mV@10 mA cm^-²) during alkaline water electrolysis. This work provides a new strategy for the controllable design of high-performance electrocatalysts, highlighting the crucial roles of both precise interfacial doping and synergistic support engineering on optimizing catalytic performance.