Formation Mechanisms of Graphitic-N: Oxygen Reduction and Nitrogen Doping of Graphene Oxides

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• 作者：Wei-Wei Wang ; Jing-Shuang Dang ; Xiang Zhao ; Shigeru Nagase
• 刊名：Journal of Physical Chemistry C
• 出版年：2016
• 出版时间：March 17, 2016
• 年：2016
• 卷：120
• 期：10
• 页码：5673-5681
• 全文大小：763K
• ISSN：1932-7455

文摘

Deoxygenation and nitrogen-doping mechanisms of graphene oxides with participation of foreign NH₃ molecules were investigated by density functional theory calculations. First, reduction on perfect graphene oxide without any structural defect is proved to be facilitated at high temperature, but the following doping process is impracticable because of the huge energy requirement for C–C cleavage. To elucidate the formation of hexagonal graphitic-N, we explored oxygen reduction and subsequent nitrogen-doping processes on defective graphene oxides with single vacancies for the first time. All possible reaction pathways were taken into account, and the results demonstrate that the formation of graphitic-N from NH₃ and defective graphene oxides with one carbonyl or two hydroxyl groups is feasible in energy. The dominant reaction route is found to be exothermic with a practical reaction rate of 2.26 × 10⁶ s^–1 at 900 °C, which is in a good agreement with experimental observations.