Integrating active Pt clusters into transition-metal oxides with water-dissociation ability is effective to prepare a bifunctional electrocatalyst for water splitting in alkaline. However, the additional utilization of a reductant and/or the operation at the elevating temperature causes the over-growth and agglomeration of Pt clusters, thus losing the high catalytic performance. Herein, we report that V dopant not only favors self-reducing Pt clusters on NiFe layered double hydroxide (LDH) (Pt/NiFeV) at room temperature, but also regulates interfacial charge redistribution to enhance the water-splitting performance. Experimental and theoretical studies reveal that V dopant into NiFe LDH triggers more electrons to transfer to adjacent Fe atoms, thus leading to a higher reducing ability compared to that without V-doping. When used as water-splitting electrocatalyst, V doping promotes electron loss of Pt clusters in Pt/NiFeV, optimizing the free energy of hydrogen adsorption and proton recombination kinetics at the cathode. Meanwhile, it also moves the d-band center of Ni away from the Fermi level to optimize the adsorption of *OH intermediates and facilitate the desorption of oxygen molecules at the anode. Thereby, Pt/NiFeV exhibits much higher bifunctional performance than V-free Pt/NiFe LDH toward both the hydrogen evolution reaction (HER) and oxygen evolution reaction (OER). This work can spark inspiration of designing other bifunctional electrocatalysts for energy conversion and storage.

将活性 Pt 簇集成到具有水离解能力的过渡金属氧化物中可有效制备用于碱性水分解的双功能电催化剂。然而，额外使用还原剂和/或在升高温度下操作会导致Pt簇的过度生长和团聚，从而失去高催化性能。在此，我们报告了 V 掺杂剂不仅有利于室温下 NiFe 层状双氢氧化物 (LDH) (Pt/NiFeV) 上的自还原 Pt 簇，而且还调节界面电荷重新分布以提高水分解性能。实验和理论研究表明，NiFe LDH 中的 V 掺杂会触发更多的电子转移到相邻的 Fe 原子，从而与没有 V 掺杂的情况相比具有更高的还原能力。当用作水分解电催化剂时，V 掺杂促进 Pt/NiFeV 中 Pt 簇的电子损失，优化氢吸附的自由能和阴极的质子复合动力学。同时，它还使Ni的d带中心远离费米能级，以优化*OH中间体的吸附并促进阳极氧分子的解吸。因此，在析氢反应（HER）和析氧反应（OER）方面，Pt/NiFeV 表现出比无 V Pt/NiFe LDH 高得多的双功能性能。这项工作可以激发设计其他用于能量转换和存储的双功能电催化剂的灵感。同时，它还使Ni的d带中心远离费米能级，以优化*OH中间体的吸附并促进阳极氧分子的解吸。因此，在析氢反应（HER）和析氧反应（OER）方面，Pt/NiFeV 表现出比无 V Pt/NiFe LDH 高得多的双功能性能。这项工作可以激发设计其他用于能量转换和存储的双功能电催化剂的灵感。同时，它还使Ni的d带中心远离费米能级，以优化*OH中间体的吸附并促进阳极氧分子的解吸。因此，在析氢反应（HER）和析氧反应（OER）方面，Pt/NiFeV 表现出比无 V Pt/NiFe LDH 高得多的双功能性能。这项工作可以激发设计其他用于能量转换和存储的双功能电催化剂的灵感。