Encapsulated RuP2–RuS2 nanoheterostructure with regulated interfacial charge redistribution for synergistically boosting hydrogen evolution electrocatalysis

Exploring cost-effective electrocatalysts with suitable hydrogen binding strength and rational micro/nano-architecture towards the hydrogen evolution reaction (HER) is crucial for energy technologies, yet remains a tough challenge. Herein we present the first instance of a nanoscale RuP2-RuS2 heterostructure encapsulated in N, P, and S co-doped porous carbon nanosheets (RuP2-RuS2/NPS-C) for boosting the HER. The synthesis involves the construction of a 2D core-shell structured precursor in which Ru3+-functionalized g-C3N4 is wrapped by poly(cyclotriphosphazene-co-4,4'-sulfonyldiphenol) followed by pyrolysis. In this nanocomposite, the unique architecture with a highly dispersed embedded RuP2-RuS2 nanoheterostructure guarantees not only full exposure of the active sites with enhanced robustness but also smooth mass/charge transfer. More significantly, the experimental results and theoretical calculations reveal that coupling RuP2 with RuS2 to construct a heterointerface can induce charge redistribution, giving rise to optimized hydrogen adsorption energy for substantially accelerating the HER. This work provides a novel strategy to engineer high-performance Ru-based electrocatalysts by elegantly modulating the micro-/nano-architecture and interface coupling effect.