二维π-共轭多孔碳网络及其环状结构单元的合成与性能研究

Featured with unusual 2D planar carbon networks and extraordinary electronic properties, the design and fabrication of graphene and related carbon materials have drawn numerous interests. However, constructing 2D planar networks and controlling their structure on the atomic scale remain as a challenging field, which also greatly hampered the exploration and development of novel carbon materials. Therefore, the bottom-up design and synthesis of novel 2D carbon materials are of great significance..Synthesizing nano-sized polyphenylene macrocycles and constructing 2D carbon networks based on these cyclic moieties will shed some lights on the relationships between the structure and function of 2D carbon materials, and further promote the manufacture of 2D carbon materials. In this proposal, the research will be aimed at the designing of novel 2D π-conjugated carbon networks based on the topological structure of well-known graphynes, synthesizing the 2D frameworks and their cyclic substructures based on tetraphenylethene and hexaphenylbenzene moieties, and exploring the possibility of fabricating porous graphene materials from these carbon networks. Their molecular geometry, optoelectronic properties, and porous structures will be investigated by using characterization methods, like NMR spectroscopy, mass spectrometry, absorption and fluorescence spectroscopy, STM and BET. Additionally, we will investigate the impacts of porous topology on the performance of carbon materials, and explore the possibility of constructing porous graphene from these 2D carbon networks..This project will study the methodology of building-up 2D π-conjugated carbon networks and their polyphenylene cyclic substructures, and fabricating porous graphene materials, and provide experimental evidence for designing novel carbon materials and investigating their structures and properties.

石墨烯具有的独特二维平面结构和不同寻常的电子特性使得与之相关碳材料的设计和制备也备受关注。构筑二维平面网络并在原子尺度上调控其结构是一个亟待解决的科学难题。因此，自下而上的设计与合成新型二维碳网络具有重要意义。.本项目拟基于石墨炔的拓扑结构提出新型二维π-共轭碳网络，将通过纳米尺度的环状结构单元构筑二维碳网络以考察其结构与功能之间的关系。以四苯基乙烯和六苯基苯等结构基元构筑二维碳网络及其结构单元，采用核磁共振、质谱、吸收和荧光光谱、扫描隧道显微镜等多种研究手段考察其分子结构、凝聚态结构、形貌及性能。同时，将考察二维碳网络的多孔结构对其性能的影响，探索通过多孔二维碳网络制备多孔石墨烯材料的新方法。.本项目的执行将促进新型碳材料的探索与发展，为研究多孔石墨烯等新型碳材料的设计与制备、结构与性能提供实验基础。

目前，以石墨烯为代表的二维碳材料，因其独特的二维平面结构和不同寻常的电子特性，在前沿材料开发与应用领域备受关注。但是二维碳材料的大规模化学合成结构控制一直是一个亟待解决的问题，而二维碳材料的可控制备极大限制了具有新型拓扑结构的二维材料的拓展。本研究致力于利用“自下而上”的有机合成方法构建二维共轭多孔碳网络及其环状结构单元，并探索在碳网络中引入纳米多孔结构及特定功能基团的可能性。.具体的，本研究以四苯基乙烯为核心结构单元，基于精巧的化学合成制备了一系列具有不同拓扑结构、边缘结构、元素组成、石墨化程度的环状多孔结构单元。通过调控前体分子化学和几何结构，我们成功赋予了多孔碳结构中孔隙特定的化学环境（如功能基团和杂原子的引入），以及几何尺寸（直径从0.4到1.0纳米）。由于多孔碳网络以具有聚集诱导发光特性的四苯基乙烯分子为核心骨架，因而该系列材料和分子均具备高的固态荧光量子产率，以及荧光响应行为。而多孔骨架中杂原子的引入使得该类材料的荧光能够选择性地被特定金属离子或有机客体分子所淬灭，从而充分说明了多孔碳网络在金属离子及催化剂负载、分子吸附与检测等领域的潜在应用前景。另外，通过调控环状结构单元边缘结构及骨架内石墨化程度，可以有效的调节该系列环状结构单元的荧光行为，从双相高效发光，到聚集诱导发光，直至聚集诱导淬灭。该结果为深入了解二维多孔碳网络的制备方法和构效关系提供了坚实的实验依据。