Acid-stable bimetallic phosphide-silver core-shell nanowires with a seamlessly conductive network for enhanced hydrogen evolution reaction

Abstract

Developing low-cost and high-performance acid-resistant electrocatalysts is essential for the industrialization of hydrogen production via proton exchange membrane water electrolysis. Herein, an acid-stable bimetal phosphide (NiCoP) catalyst wrapped around silver nanowires (Ag NWs), forming a seamless conductive core-shell structure (NiCoP@Ag NWs), is reported to enhance the hydrogen evolution reaction (HER). The incorporation of Ag NWs creates an uninterrupted conductive network that facilitates efficient electron transfer and provides a large electrolyte-accessible surface area for mass transport. The synergistic interaction among Ni, Co, and P further optimizes electronic structure and decreases the energy barrier of NiCoP@Ag NWs for H* adsorption and desorption. More importantly, the distinctive core-shell structure imparts outstanding acid resistance to the catalyst. Notably, NiCoP@Ag NWs displays remarkable HER performance, with a low overpotential of 109 mV (significantly lower than Ni₂P@Ag NWs at 144 mV and Co₂P@Ag NWs at 174 mV) at a current density of 10 mA/cm², along with excellent durability exceeding 100 h in acidic media. These features surpass most reported non-noble metal catalysts, demonstrating extraordinary potential for practical hydrogen production via acidic water electrolysis.

Graphical abstract

Keywords

bimetal phosphide / Ag nanowires (Ag NWs) / core-shell structure / hydrogen evolution reaction (HER)

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