Binary NiFe layer double hydroxide (LDH) serves as a benchmark non‐noble metal electrocatalyst for the oxygen evolution reaction, however, it still needs a relatively high overpotential to achieve the threshold current density. Herein the catalyst's electronic structure is tuned by doping vanadium ions into the NiFe LDHs laminate forming ternary NiFeV LDHs to reduce the onset potential, achieving unprecedentedly efficient electrocatalysis for water oxidation. Only 1.42 V (vs reversible hydrogen electrode (RHE), ≈195 mV overpotential) is required to achieve catalytic current density of 20 mA cm⁻² with a small Tafel slope of 42 mV dec⁻¹ in 1 m KOH solution, which manifests the best of NiFe‐based catalysts reported till now. Electrochemical analysis and density functional theory +U simulation indicate that the high catalytic activity of NiFeV LDHs mainly attributes to the vanadium doping which can modify the electronic structure and narrow the bandgap thereby bring enhanced conductivity, facile electron transfer, and abundant active sites.

中文翻译：

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钒掺杂调节NiFe层状双氢氧化物的电子结构以实现高效电催化水氧化

二元NiFe层双氢氧化物（LDH）用作氧气逸出反应的基准非贵金属电催化剂，但是，它仍需要相对较高的超电势才能达到阈值电流密度。在此，通过将钒离子掺杂到形成三元NiFeV LDH的NiFe LDH层压板中来调整催化剂的电子结构，以降低起始电势，从而实现了前所未有的高效电催化水氧化。仅需要1.42 V（相对于可逆氢电极（RHE），≈195 mV超电势）即可实现20 mA cm ^-2的催化电流密度和1 m内的42 mV dec ^-1的小Tafel斜率KOH溶液，是迄今为止报道的最好的基于NiFe的催化剂。电化学分析和密度泛函理论+ U模拟表明，NiFeV LDHs的高催化活性主要归因于钒掺杂，钒掺杂可以改变电子结构并缩小带隙，从而带来增强的电导率，便捷的电子转移和丰富的活性位点。