Interfacial Interaction between FeOOH and Ni-Fe LDH to Modulate the Local Electronic Structure for Enhanced OER Electrocatalysis
Interfacial Interaction between FeOOH and Ni-Fe LDH to Modulate the Local Electronic Structure for Enhanced OER Electrocatalysis
复制标题
FeOOH 和 Ni-Fe LDH 之间的界面相互作用调节局部电子结构以增强 OER 电催化
DOI：
10.1021/acscatal.8b03489
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发表时间：
2018-12-01
期刊：
影响因子：
12.9
通讯作者：
Sun, Shi-Gang
中科院分区：
文献类型：
--
作者：
Chen, Jiande;Zheng, Feng;Sun, Shi-Gang
为了追求高性能的Ni 2 +/Co 2 +/Fe 3 +-相关的析氧反应（OER）电催化剂，活性金属位点的局部电子结构的调节提供了基本的基序，这可以通过局部化学环境的直接修饰或与具有高电负性的第二金属基底（通常为贵金属Au）的界面相互作用来实现。在此，我们报告的本地电子结构的Ni-Fe层状双氢氧化物（LDH）可以有利地调制通过强的界面相互作用与FeOOH纳米粒子（NPs）。当FeOOH纳米颗粒的平均尺寸从18.0 nm减小到2.0 nm时，两相和多尺度复合材料FeOOH/LDH表现出越来越明显的OER催化协同效应。特别地，具有平均尺寸为2.0 nm的FeOOH NP的复合物在10 mA cm（-2）下表现出174 mV的过电位，并且在1.0 M KOH中表现出27 mV dec（-1）的塔菲尔斜率，超过了迄今为止报道的所有贵金属和非贵金属OER催化剂;它在各种稳定性测试中也平稳地运行。基于XANES和EXAFS分析、直流伏安法和大振幅交流傅立叶变换，伏安法证明存在高氧化态铁从高度不饱和的超细FeOOH NPs中分离出Fe（3 + delta）+-O键相对较短的（（3+ delta）+）位，这些位可以改革局部电子结构，并有利地操纵Ni-Fe LDH中Ni 2+物种的电子氧化和电催化行为，因此导致易于形成，优异的OER活性，以及非凡的结构和催化稳定性。我们的工作着重于Ni-Fe LDH与非贵金属组分之间的固-固界面化学在设计活性金属中心的局部电子结构中的作用，成功地将研究已久的Ni-Fe LDH的催化活性远远推高到其电流极限，为OER电催化剂的合理设计开辟了一条途径。
Toward the pursuit of high-performance Ni2+/Co2+/Fe3+-relevant oxygen evolution reaction (OER) electrocatalysts, the modulation of local electronic structure of the active metal sites provides the fundamental motif, which could be achieved either through direct modifications of local chemical environment or interfacial interaction with a second metal substrate which possesses high electronegativity (typically noble metal Au). Herein, we report that the local electronic structure of Ni-Fe layered double hydroxide (LDH) could be favorably modulated through strong interfacial interactions with FeOOH nanoparticles (NPs). The biphasic and multiscale composites FeOOH/LDH demonstrated an increasingly pronounced synergy effect for OER catalysis when the average size of FeOOH NPs decreases from 18.0 to 2.0 nm. Particularly, the composite with average size of FeOOH NPs of 2.0 nm exhibited an overpotential of 174 mV at 10 mA cm(-2) and a tafel slope of 27 mV dec(-1) in 1.0 M KOH, outmatching all the noble and non-noble OER catalysts reported so far; it also operates smoothly in various stability tests. A mechanistic study based on XANES and EXAFS analysis, d.c. voltammetry and large amplitude Fourier Transformed a.c. voltammetry proved the presence of high-oxidation-state Fe((3+delta)+)sites with relatively short Fe(3+delta)+-O bond from the highly unsaturated ultrafine FeOOH NPs which could reform the local electronic structure and favorably manipulate the electronic oxidation and thus electrocatalytic behaviors of the Ni2+ species in the Ni-Fe LDH, hence leading to the easy formation, excellent OER activity, and extraordinary structural and catalytic stability. Our work puts an emphasis on the role of the solid-solid interfacial chemistry between a Ni-Fe LDH and a non-noble-metal component in engineering the local electronic structure of the active metal sites, which successfully pushed forward the catalytic activity of the well-studied Ni-Fe LDH far beyond its current limit in OER catalysis and opened up an avenue for rational design of OER electrocatalysts.