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

Zhang, Fan; Zhang, Hui; Han, Weiwei; Yang, Shiliu; Wei, Yijun; He, Yi; Lei, Lecheng; Zhang, Xingwang · Nano Lett · 2025

basic_science · Level V

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Abstract

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 H<sub>2</sub>O dissociation during the hydrogen evolution reaction. The resulting Er<sub>0.1</sub>-CoP/NiCoP catalyst achieves a low overpotential of 154 mV at -500 mA cm<sup>-2</sup> in 1.0 M KOH. An AEM electrolyzer comprising an Er<sub>0.1</sub>-CoP/NiCoP@NF cathode demonstrates a low cell voltage of 1.672 V and stability exceeding 1000 h at 500 mA cm<sup>-2</sup> (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><sub>H*</sub>) and improve OH*/H<sub>2</sub>O* adsorption, thereby facilitating H<sub>2</sub>O dissociation and H<sub>2</sub> evolution.