A Simple Synthetic Strategy toward Defect-Rich Porous Monolayer NiFe-Layered Double Hydroxide Nanosheets for Efficient Electrocatalytic Water Oxidation
A Simple Synthetic Strategy toward Defect-Rich Porous Monolayer NiFe-Layered Double Hydroxide Nanosheets for Efficient Electrocatalytic Water Oxidation
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一种用于高效电催化水氧化的富含缺陷的多孔单层 NiFe 层状双氢氧化物纳米片的简单合成策略
DOI：
10.1002/aenm.201900881
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发表时间：
2019
影响因子：
27.8
通讯作者：
Zhang Tierui
中科院分区：
文献类型：
--
作者：
Zhang Xin;Zhao Yufei;Zhao Yunxuan;Shi Run;Waterhouse Geoffrey I. N.;Zhang Tierui
在这项工作中，多孔单层镍-铁层状双氢氧化物（PM-LDH）纳米片的横向尺寸为30 nm，厚度为0.8 nm的成功合成通过一个简单的一步策略。简单地说，在80 °C和pH 10下，将含有Ni 2+和Fe 3+的水溶液逐滴添加到甲酰胺水溶液中，仅在10分钟内形成PM-LDH产物。这种快速合成策略在单层NiFe-LDH纳米片中引入了丰富的孔，导致PM-LDH含有高浓度的氧和阳离子空位，这是由扩展X射线吸收精细结构和电子自旋共振测量证实的。PM-LDH中的氧和阳离子空位协同作用，增加了LDH纳米片的正电性，同时也增强了水电氧化过程中形成的OH* 中间体的H2O吸附和结合强度，赋予PM-LDH优异的析氧反应（OER）性能。PM-LDH在10 mA cm−2的电流密度下提供非常低的OER过电位（230 mV），Tafel斜率仅为47 mV dec−1，代表了NiFe-LDH系统迄今为止报告的最佳OER性能之一。这些结果鼓励了多孔单层LDH纳米片在电催化、催化和太阳能电池中的更广泛的利用。
In this work, porous monolayer nickel‐iron layered double hydroxide (PM‐LDH) nanosheets with a lateral size of ≈30 nm and a thickness of ≈0.8 nm are successfully synthesized by a facile one‐step strategy. Briefly, an aqueous solution containing Ni2+and Fe3+is added dropwise to an aqueous formamide solution at 80 °C and pH 10, with the PM‐LDH product formed within only 10 min. This fast synthetic strategy introduces an abundance of pores in the monolayer NiFe‐LDH nanosheets, resulting in PM‐LDH containing high concentration of oxygen and cation vacancies, as is confirmed by extended X‐ray absorption fine structure and electron spin resonance measurements. The oxygen and cation vacancies in PM‐LDH act synergistically to increase the electropositivity of the LDH nanosheets, while also enhancing H2O adsorption and bonding strength of the OH* intermediate formed during water electrooxidation, endowing PM‐LDH with outstanding performance for the oxygen evolution reaction (OER). PM‐LDH offers a very low overpotential (230 mV) for OER at a current density of 10 mA cm−2, with a Tafel slope of only 47 mV dec−1, representing one of the best OER performance yet reported for a NiFe‐LDH system. The results encourage the wider utilization of porous monolayer LDH nanosheets in electrocatalysis, catalysis, and solar cells.