Designing metal-organic framework (MOF) with controllable lattice defects and oxygen vacancies is of great significance for effective oxygen evolution reaction (OER). We achieved controlled lattice defects and generated oxygen vacancies in the Ni-MOF nanoflowers by accurately substituting Fe atoms for Ni2 atoms. The optimized NiFe-MOF/CFP exhibits remarkable OER performance (an ultra-low overpotential of 281 mV at 100 mA cm and a Tafel slope of 38 mV dec) and excellent stability (the activity maintains for 80 h at 100 mA cm). Importantly, it is revealed that the active species is the NiFe-MOF/NiFeOOH complex for OER. Density functional theory (DFT) provides the insightful catalytic mechanism that the Fe atoms and oxygen vacancies are critical in optimizing the -band center and promoting the dissociation of oxygen-containing intermediates. Our work introduces a strategy for designing defect-rich MOF-based electrocatalysts, opening up new possibilities for efficient OER systems.

中文翻译：

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准确地用 Fe 取代富含缺陷的 Ni-MOF 中的 Ni2 原子以实现高效的析氧反应：电子重构和机理研究

设计具有可控晶格缺陷和氧空位的金属有机骨架（MOF）对于有效的析氧反应（OER）具有重要意义。通过准确地用 Fe 原子代替 Ni2 原子，我们实现了可控的晶格缺陷，并在 Ni-MOF 纳米花中产生了氧空位。优化后的NiFe-MOF/CFP表现出卓越的OER性能（100 mA cm下超低过电位281 mV，Tafel斜率38 mV dec）和优异的稳定性（100 mA cm下活性保持80 h）。重要的是，研究表明 OER 的活性物质是 NiFe-MOF/NiFeOOH 复合物。密度泛函理论（DFT）提供了富有洞察力的催化机制，即Fe原子和氧空位对于优化能带中心和促进含氧中间体的解离至关重要。我们的工作引入了一种设计富含缺陷的 MOF 基电催化剂的策略，为高效 OER 系统开辟了新的可能性。