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Abstract
Hydrogen evolution reaction (HER) electrocatalysts over platinum (Pt) in an alkaline medium is crucial for hydrogen economy. Herein, we demonstrate new concept “interface-active electrode” to transform naturally inert alkaline HER materials towards industry-applicable HER electrocatalyst, comprised of interface-rich NiP2-FeP2 on Cu nanowires that required overpotential as low as 23.6 and 357 mV at -10 and -1000 mA/cm2, respectively, with exceptional stability at the industrial current density of -1 A cm-2, superior to commercial Pt under alkaline solution. Structural characterization and theoretical calculations revealed the abundant interface between facets of NiP2-FeP2 on Cu exhibits optimum H adsorption-free energy than Pt and lower kinetic barrier for water dissociation (ΔGB = 0.16 eV), boosting alkaline HER. Additionally, when integrated in a water splitting device, generated 10 mA/cm2 at only 1.42, 1.4, and 1.31 V under 1 M KOH, artificial seawater at 25 ̊C and 100 ̊C, respectively, along with high solar-to-hydrogen (STH) conversion efficiency of 19.85 %.
