Synergistic Modulation of Multisite Electronic States via Erbium Doping and NiCoP Hybridization for Enhanced Anion Exchange Membrane Water Splitting

Water dissociation in anion exchange membrane water electrolysis (AEMWE) faces significant energy barriers, posing a challenge for reducing cell voltage. Herein, we engineered CoP nanosheets by doping Er and hybridizing with NiCoP to optimize local electronic states and accelerate H₂O dissociation during the hydrogen evolution reaction. The resulting Er_0.1-CoP/NiCoP catalyst achieves a low overpotential of 154 mV at -500 mA cm^-2 in 1.0 M KOH. An AEM electrolyzer comprising an Er_0.1-CoP/NiCoP@NF cathode demonstrates a low cell voltage of 1.672 V and stability exceeding 1000 h at 500 mA cm^-2 (50 °C). Characterization, density functional theory (DFT) calculations, and ab initio molecular dynamics (AIMD) simulations reveal that Er doping and NiCoP hybridization synergistically modulate charge distribution across multisites, shifting the p-band centers away from the Fermi level. These adjustments optimize the free energy of H* adsorption (Δ<i>G</i>_H*) and improve OH*/H₂O* adsorption, thereby facilitating H₂O dissociation and H₂ evolution.