Self-Supported Bimetallic Phosphide Heterojunction-Integrated Electrode Promoting High-Performance Alkaline Anion-Exchange Membrane Water Electrolysis

Developing effective, stable, and economical catalysts toward overall water splitting under industrial conditions is crucial for the large-scale production of green hydrogen. Herein, we report a general method to fabricate bimetallic phosphide heterojunctions on nickel foam (NF) for water electrolysis. Benefiting from the unique self-supported integrated structure and optimized electronic structure, the Co 2 P–Ni 12 P 5 /NF and Fe 2 P–Ni 12 P 5 /NF heterojunction exhibits ultralow overpotentials of 219 mV for hydrogen evolution and 342 mV for oxygen evolution at 1000 mA cm –2 in 1 M KOH, respectively. Notably, the assembled two-electrode system attains a high current density of 1000 mA cm –2 with a low cell voltage of 1.678 V under simulated industrial electrolysis conditions. Furthermore, when applied in an anion-exchange membrane water electrolysis (AEMWE) cell, Co 2 P–Ni 12 P 5 /NF||Fe 2 P–Ni 12 P 5 /NF exhibits superior performance over commercial Pt/C/NF||IrO 2 /NF. Our study provides a general method for developing economical and practical water-splitting electrocatalysts for large-scale renewable hydrogen production.