新型三维多级结构石墨烯组装体的宏量合成、机理及性质研究

Using graphene as a building block to assemble ordered, advanced three dimensional structure and to utilize their effective integral function has been regarded to be an efficient way of achieving broad applications of graphene. To this end, this project will first develop a new type of chemical exfoliation technique, on the basis of microwave-assisted mild oxidation process, to quantitatively prepare colloidal solution of graphene oxides that have controllable macrostructures and properties; then, using as-prepared tellurium nano-crystals to carry out in situ reduction of graphene oxide, controllably building a variety of three-dimensional, multi level structure of new graphene assembly, especially three dimensional nano-pore graphene assemblies with an interconnection network structure. This project will explore key factors that influence the three-dimensional assembly of graphene and investigate the dynamical evolution of the multilevel structure. Through combining multi-scale modeling techniques and first principles calculations, this research is expected to decipher the driving force in the three-dimensional assembly and to reveal the principle and mechanisms of how tellurium nanocrystalline assists the assembly of graphene. Ultimately, it leads to developing a new method for achieving quantitative production of three-dimensional graphene that have controllable structures. This research will also investigate the mechanical, thermal and electrical properties of three-dimensional graphene and their relationships to the microstructure and explore their applications in high-performance supercapacitors. Results from the above proposed research will not only enrich the study on connotation of graphene, but also have significant impacts on the future development as well as the practical applications of graphene in the field of energy.

以石墨烯为构建单元，组装成三维有序高级结构并有效发挥整体的集合性能，被认为是未来实现石墨烯宏观应用的一条有效途径。为此，本项目首先发展一种微波辅助的新型温和氧化剥离技术，宏量制备结构和性能可控的氧化石墨烯胶体溶液。然后，利用现场产生的碲纳米晶原位还原氧化石墨烯，可控构筑多种具有三维多级结构特别是具有三维互通纳米多孔结构的新型石墨烯组装体。探讨影响石墨烯片三维组装的关键因素，研究石墨烯三维多级结构的动力学演化过程。结合多尺度建模技术和第一性原理计算，阐明三维组装过程中的驱动力，揭示碲纳米晶促进石墨烯三维组装的规律，进而发展一种宏量可控构筑三维多级结构石墨烯组装体的新方法。研究石墨烯的三维多级结构与其力学、热学及其电学性质的关系，探索三维多级结构石墨烯组装体在高性能超级电容器中的应用。上述结果将不仅丰富石墨烯的研究内涵，而且对未来拓展和提高石墨烯在储能领域的实际应用具有重要的意义。

三维石墨烯具有高比表面积、高孔隙率以及高导电率等优异的特性，在吸附、催化、传感以及能量转化与储存等领域具有重要的应用前景，但是高品质三维石墨烯的量化制备一直是世界性的难题。为此，本项目发展了多种新型的实验技术和方法，量化合成了系列具有新颖结构的三维石墨烯材料，并对其力学/热学/电学性质以及能量转化与储存性能等进行了深入的研究。主要工作包括：（1）开创性地发展了一种基于离子液原位聚合-碳化的量化制备新方法，规模化制备了一种由微孔石墨烯片构建的高密度(1.99 g cm-3)氮、磷共掺杂链状小球。运用该材料制备的超级电容器不仅具有目前无金属碳基材料最高的体积容量（934 F cm-3），而且具有超快的充放电性能（<1 s）和优异的循环稳定性（>60000次）；（2）发展了一种基于卤代烃原位脱卤还原的新技术，首次设计合成了一种石墨烯量子点/石墨烯纳米带杂化材料、一种三维介孔石墨烯球以及一种具有三维多级孔结构的纳米碳小球。其中，石墨烯量子点/石墨烯纳米带杂化材料作为一种无金属电催化剂，具有目前最高的氧还原催化活性和稳定性；（3）以氧化石墨烯为组装单元，通过无模板的界面反应路线，构建了一种具有多级纳米孔结构的硅-氧共健结合的还原氧化石墨烯组装体，该材料具有超强的耐冲击性能。相关研究参加国际会议3次，国内会议9次，并在J.Am.Chem.Soc.、Nanascale、ACS Appl. Mater. Interf.、Energy and Fuel以及Electrochem. Acta等学术杂志上发表SCI论文 12 篇，他引超过149次，授权发明专利11 项，并获教育部自然科学奖二等奖1项。