Dual-Function Electrocatalytic Activity Unleashed by FeMo-Graphdiyne@Ni₃S₂ with Engineered Heterointerfaces

In this study, graphdiyne (GDY) was grown in situ on sulfide surfaces derived from polyoxometalate (POM) to construct sp-C–S–M heterointerfaces between metal sulfides (Fe₃S₄ and MoS₂) and GDY, thereby enabling highly efficient bifunctional oxygen evolution reaction (OER) and hydrogen evolution reaction (HER) electrocatalysis. Experimental results reveal that the heterointerface configuration enhances the synergistic interaction between the POM-derived sulfides and GDY, promoting rapid charge transfer and increasing the number of active sites, which collectively boost the intrinsic catalytic activity. At a current density of 10 mA cm^–2, the catalyst demonstrates low overpotentials of 132 mV for the HER and 218 mV for the OER and exhibits excellent catalytic activity. This work systematically clarifies the critical roles of electronic interaction and interfacial architecture between POM-derived components and GDY in enhancing HER and OER activities, offering an effective strategy for the design and construction of high-performance electrocatalysts.