In Situ Reconstruction of V‐Doped Ni2P Pre‐Catalysts with Tunable Electronic Structures for Water Oxidation

By Tingwen Zhao, Xiangjian Shen, Yuan Wang, R. Hocking, Yibing Li, Chengli Rong, K. Dastafkan, Zhen Su, Chuan Zhao. Advanced Functional Materials, 2021

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Nickel‐based electrocatalysts are promising candidates for oxygen evolution reaction (OER) but suffer from high activation overpotentials. Herein, in situ structural reconstruction of V‐doped Ni2P pre‐catalyst to form highly active NiV oxyhydroxides for OER is reported, during which the partial dissolution of V creates a disordered Ni structure with an enlarged electrochemical surface area. Operando electrochemical impedance spectroscopy reveals that the synergistic interaction between the Ni hosts and the remaining V dopants can regulate the electronic structure of NiV oxyhydroxides, which leads to enhanced kinetics for the adsorption of *OH and deprotonation of *OOH intermediates. Raman spectroscopy and X‐ray absorption spectroscopy further demonstrate that the increased content of active β‐NiOOH phase with the disordered Ni active sites contributes to OER activity enhancement. Density functional theory calculations verify that the V dopants facilitate the generation of *O intermediates during OER, which is the rate‐determining step for realizing efficient O2 evolution. Optimization of these properties endows the NiV oxyhydroxide electrode with a low overpotential of 221 mV to deliver a current density of 10 mA cm−2 and excellent stability in the alkaline electrolyte.

Subfields: Electrical and Electronic Engineering, Electrochemistry, Renewable Energy, Sustainability and the Environment

View Paper: https://www.semanticscholar.org/paper/59fc12c6a5ab5b9a302fb2efcfec04c32ace77d4