Construction of Feδ+–Ruδ− synergistic interface enabling efficient and stable hydrogen evolution in versatile electrolytes
Electrocatalytic water splitting for hydrogen production is a key pathway for sustainable green hydrogen. However, freshwater scarcity limits large-scale application, necessitating efficient and stable catalysts for complex water sources such as seawater and wastewater. Here, we report a FeRu bimetallic nanocatalyst (FeRu-ERBC) constructed by anchoring FeRu composite nanoparticles on engineered biomass-derived carbon from Equisetum ramosissimum Desf. FeRu-ERBC exhibits excellent hydrogen evolution reaction (HER) performance in alkaline, seawater, and chemical wastewater environments, achieving an overpotential of only 22.7 mV at 10 mA·cm−2 in 1.0 M KOH and maintaining stability for over 120 h. Structural characterization and density functional theory (DFT) calculations reveal that the carbon support provides high specific surface area and hierarchical pores for mass transport, and critically promotes atomic-level substitution of Fe by Ru, forming a tightly coupled Fe–Ru interface. X-ray photoelectron spectroscopy and in situ spectroscopy confirm electron transfer from Fe to Ru, creating a 'Feδ+–Ruδ−' synergistic active center. This interface regulates the surface interfacial water network, enhancing overall reaction kinetics. This work provides a new strategy for designing Ru-based catalysts with interfacial electronic regulation for real-world water environments, highlighting the crucial role of biomass-derived carbon supports in advancing green hydrogen technology.