Ru and B co-modulated NiCoP/N-doped carbon derived from etched PBA for efficient alkaline hydrogen evolution

초록

A hierarchical Ru,B–NiCoP/NC electrocatalyst was developed for alkaline hydrogen evolution (HER) by integrating a bimetallic nickel–cobalt phosphide (NiCoP) host with B/Ru electronic modulation and a conductive N-doped carbon scaffold. The material was derived from a NiCo Prussian blue analogue via NH3-assisted etching to create an open framework, followed by polydopamine coating, phosphidation to form NiCoP/NC, boron incorporation, low-loading Ru introduction, and thermal treatment. XRD, Raman, and electron microscopy confirm crystalline NiCoP nanodomains intimately coupled to defect-rich carbon, while XPS and elemental mapping verify Ru and B incorporation without detectable Ru-rich crystallites. B incorporation is suggested to modulate the electronic/defect environment of the carbon scaffold and the phosphide–carbon heterointerface, which may be associated with enhanced utilization of low-loading Ru species and HER performance in alkaline media. In 1.0 M KOH (three-electrode), Ru,B–NiCoP/NC delivers an overpotential of 81 mV at −10 mA cm−2 and a Tafel slope of 42.67 mV dec−1, with an increased double-layer capacitance (Cdl = 2.02 mF cm−2), reduced charge-transfer resistance (Rct = 43.71 Ω), and a high H2 Faradaic efficiency of 94%. The catalyst shows durable operation, exhibiting negligible polarization change after 1000 CV cycles and retaining 97% of its initial current over 24 h at −0.15 V vs RHE. Overall, this interface-engineering strategy is likely to enhance the utilization of low-loading Ru through B-enabled electronic modulation and synergistic coupling at the NiCoP/NC heterointerface, thereby promoting efficient alkaline HER.

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