Monolayer Iron and Iron-Rich Hydroxide Nanosheets Exfoliated from High-Quality Green Rust for Enhanced Electrocatalytic Oxygen Evolution Reaction
Monolayer Iron and Iron-Rich Hydroxide Nanosheets Exfoliated from High-Quality Green Rust for Enhanced Electrocatalytic Oxygen Evolution Reaction
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DOI：
10.1021/acs.chemmater.2c03639
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发表时间：
2023-02
影响因子：
8.6
通讯作者：
Lulu Jia;Fang Xian;Y. Sugahara;Nobuyuki Sakai;Emmanuel Picheau;Hairong Xue;Y. Yamauchi;T. Sasaki;R. Ma
中科院分区：
文献类型：
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作者：
Lulu Jia;Fang Xian;Y. Sugahara;Nobuyuki Sakai;Emmanuel Picheau;Hairong Xue;Y. Yamauchi;T. Sasaki;R. Ma
Ni、Co和Fe基（羟基）氢氧化物的超薄纳米片在碱性条件下水电解中的析氧反应（OER）中表现出有前景的催化活性。研究表明，Fe可能在镍基或钴基催化剂的催化过程中发挥至关重要的作用。然而，目前缺乏有效的方法来制备和研究纯氢氧化铁纳米片。在目前的工作中，我们报道了混合价Fe2+–Fe3+层状双氢氧化物（LDH）的拓扑化学合成，即绿锈（GR），与传统合成的相比，其具有更高的质量和结晶度。厚度约为 0.8 nm 的单层 Fe2+–Fe3+LDH 纳米片源自 GR 产品。此外，采用相同方法成功制备了一系列含镍富铁LDH纳米片。所获得的富铁 LDH 纳米片的 OER 催化性能实现了较小的过电势，η = 290 mV@10 mA cm–2in 1 M KOH，其性能优于或与最活跃的 Ni-Fe LDH 催化剂相当。单层 Fe2+–Fe3+LDH 纳米片可能非常适合从分子尺度的角度探索氢氧化铁的基本物理化学性质，也可以作为与其他功能材料组装以获得混合纳米催化剂的构建块。
Ultrathin nanosheets of Ni-, Co-, and Fe-based (oxy)hydroxides exhibit promising catalytic activity for the oxygen evolution reaction (OER) in water electrolysis under alkaline conditions. It has been revealed that Fe may play a crucial role in the catalytic process of Ni- or Co-based catalysts. However, it lacks effective methods to prepare and study pure Fe hydroxide nanosheets. In the present work, we report a topochemical synthesis of mixed-valent Fe2+–Fe3+layered double hydroxides (LDHs), i.e., Green Rust (GR), featured with much higher quality and crystallinity compared to the traditionally synthesized ones. Monolayer Fe2+–Fe3+LDH nanosheets with a thickness of ∼0.8 nm were derived from the GR product. In addition, a series of Ni-bearing Fe-rich LDH nanosheets were successfully prepared by the same method. The OER catalytic performance of the obtained Fe-rich LDH nanosheets achieved a small overpotential with η = 290 mV@10 mA cm–2in 1 M KOH, which either outperforms or is comparable to the most active Ni–Fe LDH catalysts. The monolayer Fe2+–Fe3+LDH nanosheets may be ideal for exploring the fundamental physicochemical properties of iron hydroxides from a molecular-scale perspective as well as serving as a building block for the assembly with other functional materials to obtain hybrid nanocatalysts.