Ultrathin Iron‐Cobalt Oxide Nanosheets with Abundant Oxygen Vacancies for the Oxygen Evolution Reaction
Ultrathin Iron‐Cobalt Oxide Nanosheets with Abundant Oxygen Vacancies for the Oxygen Evolution Reaction
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DOI：
10.1002/adma.201606793
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发表时间：
2017-05
影响因子：
29.4
通讯作者：
L. Zhuang;L. Ge;Yisu Yang;Mengran Li;Y. Jia;X. Yao;Zhonghua Zhu
中科院分区：
文献类型：
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作者：
L. Zhuang;L. Ge;Yisu Yang;Mengran Li;Y. Jia;X. Yao;Zhonghua Zhu
电化学水分解是一种很有前途的以H2燃料形式储存光能/电能的方法;然而，它受到缓慢的阳极析氧反应（OER）的限制。为了提高H2生产的可及性，有必要通过低成本的制造路线开发具有大表面积、丰富活性位点和良好稳定性的高效OER催化剂。在此，开发了使用NaBH 4作为还原剂的简易溶液还原方法，以制备具有大比表面积（高达261.1 m2 g-1）、厚膜（1.2 nm）和重要的是丰富的氧空位的铁钴氧化物纳米片（FexCoy-ONSs）。在350 mV的过电位下测得的Fe 1Co 1-ONS的质量活性高达54.9 A g−1，而其塔菲尔斜率为36.8 mV dec−1;两者均优于商业RuO 2，结晶Fe 1Co 1-ONP和大多数报道的OER催化剂的上级。Fe 1Co 1-ONS优异的OER催化活性可归因于其特定的结构，例如，纳米片，可以促进OH−离子的质量扩散/运输，并为OER催化提供更多的活性位点，以及氧空位，可以提高电子电导率，并促进H2O吸附到附近的Co 3+位点。
Electrochemical water splitting is a promising method for storing light/electrical energy in the form of H2 fuel; however, it is limited by the sluggish anodic oxygen evolution reaction (OER). To improve the accessibility of H2 production, it is necessary to develop an efficient OER catalyst with large surface area, abundant active sites, and good stability, through a low‐cost fabrication route. Herein, a facile solution reduction method using NaBH4 as a reductant is developed to prepare iron‐cobalt oxide nanosheets (FexCoy‐ONSs) with a large specific surface area (up to 261.1 m2 g−1), ultrathin thickness (1.2 nm), and, importantly, abundant oxygen vacancies. The mass activity of Fe1Co1‐ONS measured at an overpotential of 350 mV reaches up to 54.9 A g−1, while its Tafel slope is 36.8 mV dec−1; both of which are superior to those of commercial RuO2, crystalline Fe1Co1‐ONP, and most reported OER catalysts. The excellent OER catalytic activity of Fe1Co1‐ONS can be attributed to its specific structure, e.g., ultrathin nanosheets that could facilitate mass diffusion/transport of OH− ions and provide more active sites for OER catalysis, and oxygen vacancies that could improve electronic conductivity and facilitate adsorption of H2O onto nearby Co3+ sites.