Enhancement of nitrogen and sulfur co-doping on the electrocatalytic properties of carbon nanotubes for VO2+/VO2 (+) redox reaction
Enhancement of nitrogen and sulfur co-doping on the electrocatalytic properties of carbon nanotubes for VO2+/VO2 (+) redox reaction
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氮硫共掺杂增强碳纳米管VO2 /VO2 ( )氧化还原反应电催化性能
DOI：
10.1039/c6ra27734a
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发表时间：
2017
期刊：
影响因子：
3.9
通讯作者：
He Zhangxing
中科院分区：
文献类型：
--
作者：
Li Chuanchang;Xie Baoshan;Chen Jian;He Jianjun;He Zhangxing
电极和催化剂表面上的杂原子掺杂可以影响表面和电子性质。本文以硫脲为氮源和硫源，采用热解法制备了氮硫共掺杂的多壁碳纳米管（MWCNTs-NS），并将其作为钒液流电池中VO 2 +/VO 2+氧化还原电对的电催化剂进行了研究。结果表明，热解过程对MWCNTs的微观结构没有影响。VO 2 +/VO 2+氧化还原反应MWCNTs-NS表现出更高的电化学动力学相比，原始和氮掺杂的MWCNTs。碳纳米管的氮硫共掺杂可以降低VO 2 +/VO 2+氧化还原反应的电荷转移电阻。采用静态电池，考察了碳纳米管改性石墨毡对VO 2 +/VO 2+反应的电催化性能。使用MWCNTs-NS电催化剂的电池显示出最小的电化学极化，从而导致更大的能量密度和能量效率。结果表明，MWCNTs-NS是一种新型的VO 2 +/VO 2+氧化还原催化剂，具有良好的电催化性能。
Heteroatom doping on the surface of an electrode and catalyst can impact the surface and electronic properties. Herein, nitrogen and sulfur co-doped multi-walled carbon nanotubes (denoted as MWCNTs-NS) prepared via a pyrolysis method, in which thiourea served as both nitrogen and sulfur sources, were investigated as an electrocatalyst for the VO2+/VO2+ redox couple in vanadium redox flow battery. It was revealed that the pyrolysis process had no effect on the microstructure of MWCNTs. The VO2+/VO2+ redox reaction on MWCNTs-NS exhibited higher electrochemical kinetics when compared with that on pristine and nitrogen-doped MWCNTs. The nitrogen and sulfur co-doping for MWCNTs can decrease the charge transfer resistance of the VO2+/VO2+ redox reaction. Static cells using graphite felt modified by the MWCNTs samples were employed to evaluate their electrocatalytic properties for the VO2+/VO2+ reaction. The cell using the MWCNTs-NS electrocatalyst showed the smallest electrochemical polarization, resulting in a larger energy density and energy efficiency. The results indicate that MWCNTs-NS is a novel efficient catalyst for the VO2+/VO2+ redox reaction with excellent electrocatalytic properties.