Construction of Fe^δ+–Ru^δ− synergistic interface enabling efficient and stable hydrogen evolution in versatile electrolytes

Electrocatalytic water splitting for hydrogen production is an important pathway for achieving sustainable green hydrogen production. However, the shortage of freshwater resources limits its large-scale application, making it urgent to develop efficient and stable catalysts suitable for complex water sources, such as seawater and wastewater. In this study, a FeRu bimetallic nanocatalyst (Fe-Ru composite nanoparticles anchored on engineered biomass-derived carbon (FeRu-ERBC)) was constructed through biomass-derived two-dimensional porous carbon supports. It demonstrated excellent hydrogen evolution performance in alkaline, seawater, and chemical wastewater environments: with an overpotential of only 22.7 mV (10 mA·cm⁻²) in 1.0 M KOH and over 120 h of operational stability. Structural characterization and mechanistic studies, complemented by density functional theory (DFT) calculations, revealed that the support not only provides a high specific surface area and mass transport channels but also promotes atomic-level replacement of Fe by Ru, forming a tightly coupled Fe–Ru interface. X-ray photoelectron spectroscopy and in situ spectroscopy confirmed the electronic transfer from Fe to Ru at the interface, forming a “Fe^δ+–Ru^δ−” synergistic active center. This structure induced the regulation of the surface interfacial water network, thereby enhancing the overall reaction kinetics. This work provides a new strategy for the design of Ru-based catalysts with interface electronic regulation for real-world water environments and highlights the crucial role of biomass carbon supports in advancing green hydrogen technology.