SynergisticModulation of Multisite Electronic Statesvia Erbium Doping and NiCoP Hybridization for Enhanced Anion ExchangeMembrane 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.