Phosphorous Incorporated PtNi Networks with Synergistic Directional Electron Transfer for Efficient and Durable Seawater Hydrogen Production

Abstract The abundant chloride ions in seawater, which poison and corrode electrode materials, are the main reason for the low performance of Pt‐based catalysts toward hydrogen evolution reaction (HER) in seawater. Coupling Pt with oxophilic transition metals can enhance the activity of Pt‐based electrocatalysts, but their long‐term stability is still unsatisfactory. Herein, a small number of phosphorous atoms (from 1.2 to 5.9 at%) are precisely incorporated into PtNi networks (P‐PtNi networks) via a facile aqueous reduction strategy at room temperature. Experimental measurements and theoretical calculations prove that P incorporation leads to a synergistic directional electron transfer from P and Ni to Pt, resulting in improved water dissociation kinetics, enhanced Cl^– resistance and facilitated hydrogen adsorption. Consequently, P‐PtNi networks exhibit outstanding HER activities with a lower overpotential of 37 mV at 10 mA cm⁻² and an 8.5‐fold higher mass activity at –0.07 V compared to commercial Pt/C and only slightly lowered potential after 120 h of testing in alkaline simulated seawater. Furthermore, P‐PtNi networks show an ultrahigh solar‐to‐hydrogen efficiency of 15.2% for solar cell‐driven hydrogen production from seawater. This work sheds new lights on the design of high‐performance Pt‐based nanomaterials toward practical applications of seawater hydrogen production.