Surface Fluorination Engineering of NiFe Prussian Blue Analogue Derivatives for Highly Efficient Oxygen Evolution Reaction
Surface Fluorination Engineering of NiFe Prussian Blue Analogue Derivatives for Highly Efficient Oxygen Evolution Reaction
复制标题
用于高效析氧反应的 NiFe 普鲁士蓝类似物衍生物的表面氟化工程。
DOI：
10.1021/acsami.0c20886
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发表时间：
2021-01-22
影响因子：
9.5
通讯作者：
Huang, Baibiao
中科院分区：
文献类型：
--
作者：
Ma, Fahao;Wu, Qian;Huang, Baibiao
表面工程对于降低析氧反应(OER)的反应势垒具有重要意义。本文以NiFe-PBAS为原料，通过氟化反应制得了具有多能级结构的NiFe普鲁士蓝类似物(NiFe-PBA)-F催化剂，该催化剂在碱性溶液中10 mA/cm-2时具有190 mV的超低过电势，Tafel斜率为57 mV dec-1，稳定性良好。有趣的是，表面氟化工程可以实现对氰基配体的可控去除，有助于保持NiFe-PBAS的骨架结构。特别是，NiFe-PbAs-F发生了剧烈的重构，F离子的动态迁移创造了更多的F掺杂NiFeOOH活性中心，并提供了更有利的氧中间体吸附。密度泛函理论计算表明，F掺杂增加了Ni3d轨道在费米能级附近的态密度，从而改善了NiFeOOH的导电性。在此基础上，提出了NiFe-PbAs-F的晶格氧氧化机理。我们的工作不仅为实现NiFe-PBAS的可控热解提供了一条新的途径，而且为OER过程的重构和机理提供了更多的见解。
Surface engineering is of importance to reduce the reaction barrier of oxygen evolution reaction (OER). Herein, the NiFe Prussian blue analogue (NiFe-PBA)-F catalyst with a multilevel structure was obtained from NiFe-PBAs via a fluorination strategy, which presents an ultralow OER overpotential of 190 mV at 10 mA cm-2 in alkaline solution, with a small Tafel slope of 57 mV dec-1 and excellent stability. Interestingly, surface fluorination engineering could achieve a controllable removal of ligands of the cyan group, contributing to keep the framework structure of NiFe-PBAs. Particularly, NiFe-PBAs-F undergoes a dramatic reconstruction with the dynamic migration of F ions, which creates more active sites of F-doped NiFeOOH and affords more favorable adsorption of oxygen intermediates. Density functional theory calculations suggest that F doping increases the state density of Ni 3d orbital around the Fermi level, thus improving the conductivity of NiFeOOH. Furthermore, based on our experimental results, the lattice oxygen oxidation mechanism for NiFe-PBAs-F was proposed. Our work not only provides a new pathway to realize the controllable pyrolysis of NiFe-PBAs but also gives more insights into the reconstruction and the mechanism for the OER process.