Highly Active Fe Sites in Ultrathin Pyrrhotite Fe(7)S(8) Nanosheets Realizing Efficient Electrocatalytic Oxygen Evolution.
Highly Active Fe Sites in Ultrathin Pyrrhotite Fe(7)S(8) Nanosheets Realizing Efficient Electrocatalytic Oxygen Evolution.
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超薄磁黄铁矿 Fe7S8 纳米片中的高活性 Fe 位点实现高效电催化析氧
DOI：
10.1021/acscentsci.7b00424
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发表时间：
2017-11-22
影响因子：
18.2
通讯作者：
Xie Y
中科院分区：
文献类型：
--
作者：
Chen S;Kang Z;Zhang X;Xie J;Wang H;Shao W;Zheng X;Yan W;Pan B;Xie Y
确定电催化剂中的活性中心对于理解电催化分解水的机理是必不可少的。Ni-Fe基化合物作为碱性介质中最具活性的析氧反应催化剂之一，引起了人们极大的关注，但Ni和Fe位在其中所起的作用仍存在争议。在此，以具有混合价态和金属导电性的磁黄铁矿Fe 7S 8纳米片为例，我们说明Fe可以是电催化析氧的高活性位点。结果表明，Fe 7S 8纳米片中的离域电子可以促进体系的电子转移过程，其中Fe Ⅱ和Fe Ⅲ的d轨道在催化反应过程中相互重叠，使Fe 7S 8纳米片成为水氧化的最有效的铁基电催化剂.正如预期的那样，Fe 7S 8纳米片具有良好的电催化析氧活性，具有0.27 V的低过电位和300 mA cm-2的大电流密度在0.5 V。这项工作提供了坚实的证据，铁可能是一个有效的活性位点的电催化水裂解。超薄磁黄铁矿Fe 7S 8纳米片的混合价态和金属导电性被证明是有效的电催化剂的析氧反应与高活性的铁网站。
Identification of active sites in an electrocatalyst is essential for understanding of the mechanism of electrocatalytic water splitting. To be one of the most active oxygen evolution reaction catalysts in alkaline media, Ni–Fe based compounds have attracted tremendous attention, while the role of Ni and Fe sites played has still come under debate. Herein, by taking the pyrrhotite Fe7S8 nanosheets with mixed-valence states and metallic conductivity for examples, we illustrate that Fe could be a highly active site for electrocatalytic oxygen evolution. It is shown that the delocalized electrons in the ultrathin Fe7S8 nanosheets could facilitate electron transfer processes of the system, where d orbitals of FeII and FeIII would be overlapped with each other during the catalytic reactions, rendering the ultrathin Fe7S8 nanosheets to be the most efficient Fe-based electrocatalyst for water oxidation. As expected, the ultrathin Fe7S8 nanosheets exhibit promising electrocatalytic oxygen evolution activities, with a low overpotential of 0.27 V and a large current density of 300 mA cm–2 at 0.5 V. This work provides solid evidence that Fe could be an efficient active site for electrocatalytic water splitting. Ultrathin pyrrhotite Fe7S8 nanosheets with mixed valence states and metallic conductivity are demonstrated to be efficient electrocatalysts for oxygen evolution reaction with highly active Fe sites.
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影响因子：
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作者：
KIM, SH;TRYK, DA;SCHERSON, D
通讯作者：
SCHERSON, D
影响因子：
16.6
作者：
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通讯作者：
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8.4
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作者：
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影响因子：
16.6
作者：
Bao, Jian;Zhang, Xiaodong;Xie, Yi
通讯作者：
Xie, Yi