Nitrogen-Doped Graphene with Pyridinic Dominance as a Highly Active and Stable Electrocatalyst for Oxygen Reduction

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• 作者：Jingjie Wu ; Lulu Ma ; Ram Manohar Yadav ; Yingchao Yang ; Xiang Zhang ; Robert Vajtai ; Jun Lou ; Pulickel M. Ajayan
• 刊名：ACS Applied Materials & Interfaces
• 出版年：2015
• 出版时间：July 15, 2015
• 年：2015
• 卷：7
• 期：27
• 页码：14763-14769
• 全文大小：426K
• ISSN：1944-8252

文摘

The nitrogen-doped graphene (NG) with dominance of the pyridinic-N configuration is synthesized via a straightforward process including chemical vapor deposition (CVD) growth of graphene and postdoping with a solid nitrogen precursor of graphitic C₃N₄ at elevated temperature. The NG fabricated from CVD-grown graphene contains a high N content up to 6.5 at. % when postdoped at 800 掳C but maintains high crystalline quality of graphene. The obtained NG exhibits high activity, long-standing stability, and outstanding crossover resistance for electrocatalysis of oxygen reduction reaction (ORR) in alkaline medium. The NG treated at 800 掳C shows the best ORR performance. Further study of the dependence of ORR activity on different N functional groups in these metal-free NG electrodes provides deeper insights into the origin of ORR activity. Our results reveal that the pyridinic-N tends to be the most active N functional group to facilitate ORR at low overpotential via a four-electron pathway.