过电位
钴
材料科学
析氧
催化作用
氧化还原
电化学
化学工程
氧气
无机化学
碳纤维
电极
化学
物理化学
有机化学
复合材料
复合数
工程类
冶金
作者
Yufei Zhao,Jinqiang Zhang,Wenjian Wu,Xin Guo,Pan Xiong,Hao Líu,Guoxiu Wang
出处
期刊:Nano Energy
[Elsevier]
日期:2018-12-01
卷期号:54: 129-137
被引量:180
标识
DOI:10.1016/j.nanoen.2018.10.008
摘要
Developing low-cost and efficient catalysts for oxygen evolution reactions (OER) with both excellent activity and robust stability remains a great challenge. Herein, we report a facile spontaneous redox reaction to grow cobalt-doped MnO2 ultrathin nanosheets in situ with abundant oxygen vacancies vertically aligned on cobalt/nitrogen co-functionalized carbon nanofibers (Co-MnO2|OV) as an efficient OER catalyst. It is confirmed that metallic cobalt plays a critical role in the formation of long and ultrathin MnO2 nanosheets during the redox reaction. Furthermore, the cobalt ions doped into MnO2 significantly enhance the catalytic activity of MnO2 nanosheets. Benefiting from the collaborative advantages of doping strategy, fast charge transfer kinetics and strong synergistic coupling effects, Co-MnO2|OV composites exhibit an excellent catalytic activity and a good durability for electrochemical water oxidation, reaching 10 mA cm−2 at an overpotential of 279 mV. According to the density functional theory (DFT) calculations, the enhanced catalytic activity mainly originates from a better conductivity and the decreased adsorption energy barrier of OH- on the O sites neighboring the doped Co and oxygen vacancies. Our findings suggest that the control over the structure and composition of the materials can achieve highly efficient oxygen evolution electrocatalysts.
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