Industry-applicable, efficient hydrogen evolution reaction through an interface-activated bimetallic electrode with seawater photolysis in alkaline media

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 NiP 2 -FeP 2 on Cu nanowires that required overpotential as low as 23.6 and 357 mV at -10 and -1000 mA/cm 2 , 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 NiP 2 -FeP 2 on Cu exhibits optimum H adsorption-free energy than Pt and lower kinetic barrier for water dissociation (Δ G B = 0.16 eV), boosting alkaline HER. Additionally, when integrated in a water splitting device, generated 10 mA/cm 2 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 %.