Creation of Ge–Nx–Cy Configures in Carbon Nanotubes: Origin of Enhanced Electrocatalytic Performance for Oxygen Reduction Reaction

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• 作者：Xilin She ; Qianqian Li ; Na Ma ; Jin Sun ; Dengwei Jing ; Chengmeng Chen ; Lijun Yang ; Dongjiang Yang
• 刊名：ACS Applied Materials & Interfaces
• 出版年：2016
• 出版时间：April 27, 2016
• 年：2016
• 卷：8
• 期：16
• 页码：10383-10391
• 全文大小：599K
• 年卷期：0
• ISSN：1944-8252

文摘

High-performance nitrogen and germanium codoped carbon nanotubes (N–Ge–CNTs) were synthesized as oxygen reduction reaction (ORR) catalysts by one-step sintering of carboxyethyl germanium sesquioxide and multiwalled CNTs in NH₃ atmosphere. The ORR electrocatalytic activity evaluation was performed by using limited current density, selective reaction pathway, onset potential, H₂O₂ yields, and kinetic current density. In comparison with Ge or N solely doped CNTs, the codoped samples display more excellent ORR catalytic performance. It was observed that the codoped GeN₃C, GeN₄, and GeN₄ + NC₃ microstructures in N–Ge–CNTs are crucial to improving ORR catalytic performance, such as ideal 4 electron pathway (3.95) and positive onset potential (−0.08 V). The high ORR performance is attributed to the synergistic effect of N and Ge doping, which is capable of activating the π electrons of sp² hybridized orbital around carbon nantotubes. The ORR catalytic synergistic effect has also been verified by calculating the work function on the basis of density functional theory (DFT).