Balancing electron transfer and intermediate adsorption ability of bifunctional catalysts via tailoring electronic structures is crucial for green hydrogen production, while it still remains challenging due to lacking efficient strategies. Herein, one efficient and universal strategy is developed to greatly regulate electronic structures of the metallic Ni-Fe-P catalysts via in-situ introducing the rare earth (RE) atoms (Ni-Fe-RE-P, RE = La, Ce, Pr, and Nd). Accordingly, the as-prepared optimal Ni-Fe-Ce-P/CC self-supported bifunctional electrodes exhibited superior electrocatalytic activity and excellent stability with the low overpotentials of 247 and 331 mV at 100 mA cm for HER and OER, respectively. In the assembled electrolyzer, the Ni-Fe-Ce-P/CC as bifunctional electrodes displayed low operation potential of 1.49 V to achieve a current density of 10 mA cm, and the catalytic performance can be maintained for 100 h. Experimental results combined with density functional theory (DFT) calculation reveal that Ce doping leads to electron decentralization and crystal structure distortion, which can tailor the band structures and -band center of Ni-Fe-P, further increasing conductivity and optimizing intermediate adsorption energy. Our work not only proposes a valuable strategy to regulate the electron transfer and intermediate adsorption of electrocatalysts via RE atoms doping, but also provides a deep understanding of regulation mechanism of metallic electrocatalysts for enhanced water splitting.

中文翻译：

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通过4f-2p-3d电子相互作用平衡金属Ni-Fe-RE-P双功能催化剂的电子转移和中间吸附能力以增强水分解

通过定制电子结构平衡双功能催化剂的电子转移和中间体吸附能力对于绿色氢生产至关重要，但由于缺乏有效的策略，这仍然具有挑战性。在此，开发了一种有效且通用的策略，通过原位引入稀土（RE）原子（Ni-Fe-RE-P，RE = La，Ce， Pr、Nd）。因此，所制备的最佳Ni-Fe-Ce-P/CC自支撑双功能电极表现出优异的电催化活性和优异的稳定性，对于HER和OER在100 mA cm下分别具有247和331 mV的低过电势。在组装的电解槽中，Ni-Fe-Ce-P/CC作为双功能电极表现出1.49 V的低工作电位，实现10 mA cm的电流密度，催化性能可保持100 h。实验结果结合密度泛函理论（DFT）计算表明，Ce掺杂导致电子分散和晶体结构畸变，可以调整Ni-Fe-P的能带结构和能带中心，进一步提高电导率并优化中间吸附能。我们的工作不仅提出了通过稀土原子掺杂来调节电催化剂的电子转移和中间吸附的有价值的策略，而且还提供了对金属电催化剂增强水分解的调节机制的深入理解。