规则氮掺杂石墨烯纳米带的制备与表征研究

Substitutional doping of nitrogen atoms into the carbon lattice has been considered as an effective way to tailor the properties of graphene. In particular, the band gap of graphene would open upon the doping and makes it promising for the wide application in electronics. However, all the three kinds of well known nitrogen dopants (pyridinic N, pyrrolic N and graphitic N) can be found in the samples prepared by the current methods and the distribution of the dopants are quite random as well. The lack of control of both the types and sites of dopants highly restricts their further applications. In this project, we propose to synthesis graphene nanoribbons with regular nitrogen dopants via surface polymerization under ultra high vaccum. By carefully introduce the nitrogen atoms in the precursor molecules, graphene with different types of nitrogen dopants can be prepared controllably. Combined with scanning tunneling microscopy/spectroscopy and angle resolved photoemission spectroscopy, our study can then help to under the perturbation of electronic states of graphene upon pyridinic N, pyrrolic N and graphitic N substitutional doping, respectively.

氮掺杂是扩展石墨烯物理和化学性质的有效手段。特别是，石墨烯中替代掺杂氮原子可以打开导带和价带间的带隙，这使得其在电子领域中的应用成为可能。然而，现有的方法所制备的掺杂石墨烯样品中能够同时发现吡啶氮、吡咯氮和石墨氮这三种不同类型的氮掺杂，掺杂的位置也非常随机。这种掺杂类型和掺杂分布的不可控严重制约了石墨烯器件的发展。在本项目中，我们通过先导分子在超高真空中表面反应的方法可控地制备具有周期性单一类型氮替代掺杂的石墨烯纳米带。通过对反应先导分子的合理设计，我们将能够分别制备吡啶氮掺杂石墨烯、吡咯氮掺杂石墨烯和石墨氮掺杂石墨烯。在此基础上，利用扫描隧道显微镜/谱和角分辨光电子能谱，我们将详细研究不同的氮掺杂类型对石墨烯电子结构的影响。

石墨烯由于其独特的性能，得到了广泛的应用。为了打开石墨烯的带隙，本项目采用表面合成技术在超高真空中制备石墨烯纳米带。本项目主要的研究内容有以下三点：1，对表面合成机理的理解；2，阐明热力学与动力学因素对表面合成的影响；3，制备石墨烯纳米带。.在本项目的支持下，我们取得了如下成果:1，阐明了氧-金属衬底相互作用在碳氢键活化中的重要性；2，定量阐明了热力学因素是如何影响表面合成产物的形成。3，首次合成了宽度为5的扶手椅（armchair）型石墨烯纳米带，并研究了其电子结构。.在本项目的支持下，我们共发表SCI文章7篇，包括3篇JACS和一篇Angew. Chem. Int. Ed..