Rational design of active oxygen evolution reaction (OER) catalysts is critical for the overall efficiency of water electrolysis. The differing spin states of the OER reactants and products is one of the factors that slows OER kinetics. Thus, spin conservation plays a crucial role in enhancing OER performance. In this work, ferromagnetic (FM)–antiferromagnetic (AFM) Fe₃O₄@Ni(OH)₂ core–shell catalysts are designed. The interfacial FM–AFM coupling of these catalysts facilitates selective removal of electrons with spin direction opposing the magnetic moment of FM core, improving OER kinetics. The shell thickness is found critical in retaining the coupling effect for OER enhancement. The magnetic domain structure of the FM core also plays a critical role. With a multiple domain core, the applied magnetic field aligns the magnetic domains, optimizing the electron transport process. A significant enhancement of OER activity is observed for the multiple domain core catalysts. With a single-domain FM core with ordered magnetic dipoles, the spin-selective electron transport with minimal scattering is facilitated even without an applied magnetic field. A magnetism/OER activity model therefore hypothesizes that depends on two main parameters: interfacial spin coupling and domain structure. These findings provide new design principles for active OER catalysts.

中文翻译：

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具有自旋守恒用于水氧化的铁磁-反铁磁耦合核-壳纳米粒子

活性氧析出反应 (OER) 催化剂的合理设计对于水电解的整体效率至关重要。OER 反应物和产物的不同自旋状态是减慢 OER 动力学的因素之一。因此，自旋守恒在提高 OER 性能方面起着至关重要的作用。在这项工作中，铁磁 (FM)-反铁磁 (AFM) Fe ₃ O ₄ @Ni(OH) ₂设计了核壳催化剂。这些催化剂的界面 FM-AFM 耦合促进了自旋方向与 FM 核心磁矩相反的电子的选择性去除，从而改善了 OER 动力学。发现壳厚度对于保持 OER 增强的耦合效应至关重要。FM 磁芯的磁畴结构也起着关键作用。使用多畴核心，施加的磁场对齐磁畴，优化电子传输过程。观察到多域核心催化剂的 OER 活性显着增强。使用具有有序磁偶极子的单畴 FM 核心，即使没有施加磁场，也可以促进具有最小散射的自旋选择性电子传输。因此，磁性/OER 活动模型假设取决于两个主要参数：界面自旋耦合和域结构。这些发现为活性 OER 催化剂提供了新的设计原则。