Instituto de Ciência e Tecnologia, Universidade Federal de São Paulo , 12231-280, São José dos Campos, SP, Brazil.
Department of Chemistry, University of Southern California , Los Angeles, California 90089, United States.
J Am Chem Soc. 2015 Sep 16;137(36):11688-94. doi: 10.1021/jacs.5b05890. Epub 2015 Sep 1.
Two-dimensional alloys of carbon and nitrogen draw strong interest due to prospective applications in nanomechanical and optoelectronic devices. The stability of these chemical structures can vary greatly as a function of chemical composition and structure. The present study employs hybrid density functional theory and reactive molecular dynamics simulations to elucidate how many nitrogen atoms can be incorporated into the graphene sheet without destroying it. We conclude that (1) the C/N = 56:29 structure and all nitrogen-poorer structures maintain stability at 1000 K; (2) the stability suffers greatly in the presence of N-N bonds; and (3) distribution of electron density depends heavily on the structural pattern in the N-doped graphene. Our calculations support the experimental efforts aimed at production of highly N-doped graphene and generate important insights into the mechanisms of tuning graphene mechanical and optoelectronic properties. The theoretical prediction can be tested directly by chemical synthesis.
由于在纳米机械和光电设备中的应用前景，碳氮二维合金引起了强烈的兴趣。这些化学结构的稳定性可以随化学成分和结构的变化而有很大的变化。本研究采用杂化密度泛函理论和反应分子动力学模拟来阐明在不破坏石墨烯片的情况下可以掺入多少个氮原子。我们的结论是：(1) C/N = 56:29 结构和所有氮较少的结构在 1000 K 时保持稳定；(2) 存在 N-N 键时稳定性大大降低；(3) 电子密度的分布在很大程度上取决于氮掺杂石墨烯的结构模式。我们的计算支持旨在生产高氮掺杂石墨烯的实验努力，并为调节石墨烯机械和光电性能的机制提供了重要的见解。理论预测可以通过化学合成直接测试。
