F-Mediated Precise Control Over Amorphous/Crystalline Fe/Ni-Based Phosphides Heterostructure for Efficient Oxygen Evolution Reaction

en Transition metal-based amorphous/crystalline (a/c) heterostructured catalysts have garnered significant attention due to their exceptional activity, stability, and cost-effectiveness. However, the precise synergistic regulation of interfacial composition and phase states remains challenging. Herein, we propose an innovative strategy for the controllable synthesis of a/c heterostructures using MIL-100(Mn) template. By leveraging the intrinsic coordination disparity between Ni 2+ and Fe 3+ to drive phase separation, combined with F − mediated ion exchange-phosphidation synergy, we successfully constructed an amorphous FeP x /crystalline Ni 2 P heterostructure (a-(F, Fe)P x /Ni 2 P) with precise compositional control. Systematic investigations reveal that F − not only enhances metal ion exchange through complex stabilization but also induces amorphous/crystalline phase separation via electronic modulation. Meanwhile, a deep reconstruction process occurs under high voltage, transforming the catalyst into active F-Fe/NiOOH species, which further enhances the catalytic activity and durability. Benefiting from the synergistic effects of heterointerface electronic coupling and deep reconstruction, the as-prepared a-(F, Fe)P x /Ni 2 P catalyst exhibits exceptional oxygen evolution reaction (OER) performance in 1 M KOH, delivering an ultralow overpotential of 278 mV at 30 mA cm −2 and maintaining excellent stability over 100 h with negligible degradation. This work establishes a novel “coordination difference-driven, fluorine-mediated” interface engineering strategy, offering valuable insights for the rational design of high-performance heterostructured electrocatalysts. 摘要 zh 基于过渡金属的非晶/晶体异质结构催化剂因其卓越的活性、稳定性和成本效益而备受关注。然而,对其界面组成与相态的精确协同调控仍面临挑战。在此,我们提出了一种利用MIL-100(Mn)模板可控合成非晶/晶体异质结构的新颖策略。通过利用Ni 2+ 与Fe 3+ 之间的本征配位差异驱动相分离,并结合F − 介导的离子交换-磷化协同作用,我们成功构建了具有精确组分调控的非晶FeP x /晶体Ni 2 P异质结构(标记为a-(F, Fe) P x /Ni 2 P)。系统研究表明,F − 不仅通过络合稳定作用增强了金属离子交换效率,还通过电子调控诱导了非晶/晶体相分离。同时,催化剂在高电位下发生深度重构过程,转变为活性的F-Fe/NiOOH物种,从而进一步增强了催化活性与耐久性。受益于异质界面电子耦合与深度重构的协同效应,所制备的a-(F, Fe)P x /Ni 2 P催化剂在1 M KOH电解液中表现出优异的析氧反应性能,在30 mA cm −2 电流密度下仅需278 mV的极低过电位,并能稳定运行超过100 h而无明显衰减。本研究确立了一种全新的“配位差异驱动、氟离子介导”的界面工程策略,为合理设计高性能异质结构电催化剂提供了有价值的见解。