Although metal‐organic frameworks have proven to be excellent electrocatalytic materials, their application as electrode materials remains limited. The preparation of heterostructures is considered an effective method to improve catalytic activity. Herein, we describe the design and assembly of a dual‐MOF heterostructure (CoNi−ZIF‐67@Fe−MIL‐100, denoted ZIF@MIL). Specifically, we grew a layer of MIL‐100 in situ on a bimetallic ZIF‐67 surface using a solvothermal method. We demonstrate that the ZIF@MIL has remarkable OER electrocatalytic performance, requiring a low overpotential and showing a small Tafel slope, compared to pure ZIF‐67 and MIL‐100 in 1.0 m KOH. More importantly, it has excellent operational durability for 50 h at 100 mA cm⁻². The high catalytic activity of ZIF@MIL can be attributed to the heterostructure that can expose more active sites, the synergistic effect between ZIF‐67 and MIL‐100, and improvement of electron transfer ability. Our work provides a new way to design and prepare dual‐MOF crystals with different structures as electrocatalysts.

中文翻译：

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制备双MOF异质结构（ZIF @ MIL）以增强氧气释放反应活性

尽管金属有机骨架已被证明是出色的电催化材料，但其作为电极材料的应用仍然受到限制。杂结构的制备被认为是提高催化活性的有效方法。在这里，我们描述了双MOF异质结构（CoNi-ZIF-67 @ Fe-MIL-100，表示为ZIF @ MIL）的设计和组装。具体而言，我们使用溶剂热法在双金属ZIF-67表面上原位生长了MIL-100。我们证明，与1.0 m KOH中的纯ZIF-67和MIL-100相比，ZIF @ MIL具有卓越的OER电催化性能，要求低过电势并表现出小的Tafel斜率 。更重要的是，它在100 mA cm ^{-2的条件下}具有出色的50小时运行耐久性。ZIF @ MIL的高催化活性可以归因于可以暴露更多活性位的异质结构，ZIF-67和MIL-100之间的协同效应以及电子转移能力的提高。我们的工作提供了一种设计和制备具有不同结构的双MOF晶体作为电催化剂的新方法。