基于表面在位反应的石墨烯纳米筛的精准合成

Graphene nanomesh, a continuous two-dimensional (2D) graphene nanostructure with the ordered nanoscale holes punched in the basal plane, possesses high surface area and excellent electronic properties, showing significant potential applications in flexible electronics and biosensor. The electronic structure of graphene nanomesh is intimately related to its atomic structure. However, it is still a great challenge to control the synthesize of graphene nanomesh at atomic level. Here, we propose the bottom-up precise synthesis of graphene nanomeshes by using on-surface reaction of well-designed molecular precursors. In order to obtain large-area and highly-ordered 2D graphene nanomesh, we proposed two strategies to control the synthesis, those are, self-assembly restricted reaction and hierarchical synthesis. Firstly, we aim to acquire the specific self-assembly structures by investigating substrate-molecular interaction, and then achieve graphene namomesh by self-assembly restricted reaction. Secondly, we will induce hierarchical synthesis to improve the quality of graphene nanomesh using the well-designed molecular precursor with sequentially activated reactive sites. The atomic and electronic structures of the as-prepared graphene nanomeshes can be characterized in-situ with high resolution by scanning tunneling microscopy and scanning tunneling spectroscopy. It is expected to reveal the influence of atomic structure on the electronic structure of graphene nanomesh with the synergistic efforts between experimental studies and density functional theory calculations.

石墨烯纳米筛是一类具有有序孔洞的连续二维石墨烯结构，凭借其高比表面积和优异的电学性质，在柔性电子与生物传感等领域具有重要的应用前景。石墨烯纳米筛的能带结构与其精细原子结构密切相关，因此实现其原子尺度上的可控合成具有重要意义。但是，目前关于石墨烯纳米筛的精准合成仍然面临巨大挑战。本项目计划从分子前驱体的设计出发，利用可控的表面在位反应实现石墨烯纳米筛的精准合成。为了制备大面积、高有序性的石墨烯纳米筛，拟采用自组装限域和分步合成两种策略。首先，通过系统研究基底对分子自组装的影响，筛选出合适的自组装结构，原位诱导反应就近发生，实现自组装限域的表面反应。其次，设计合成具有不同活性基团的前驱体分子，利用其反应活性的差异分步偶联制备高质量石墨烯纳米筛。对所制备的石墨烯纳米筛，采用扫描隧道显微镜与扫描隧道谱进行原子与电子结构的高分辨原位表征，并结合理论计算分析原子精细结构对其电子结构的影响。

石墨烯纳米筛是一类具有有序孔洞的纳米石墨烯结构，由于其优异的电学性质和高比表面积，在柔性电子与生物传感领域具有重要的应用前景。石墨烯纳米筛的能带结构与其原子结构密切相关。因此实现石墨烯纳米筛在原子尺度上的可控合成是研究的关键。本项目设计并合成了多种具有不同活性基团的前驱体分子，通过系统研究分子在不同单晶衬底表面的自组装行为，探讨了分子的活性基团、衬底的组分和结构以及生长动力学对自组装结构的影响。在此基础上，对制备的自组装结构进行退火处理，并精确调控退火温度诱导分子在单晶衬底上分步活化与偶联，同时控制自组装结构中的分子与相邻分子就近偶联，实现了自组装结构对表面在位反应的调控，最终制备了具有有序结构的石墨烯纳米筛。本项目的研究为表面在位反应的调控以及类石墨烯结构的精准构筑提供了重要思路。