聚合物模板法组装石墨烯三维有序多孔材料

As two-dimensional carbon nano-materials, graphene has widely application for its excellent physical and chemical properties. Recently, to assemble individual graphene into macroscopic flexible films, hybrids as well as porous foams in a certain manner, while maintain the nano-effects of which, has become an efficient and effective approach towards scale-up application of graphene. Porous graphene macro-assembly has many advantages in energy related areas due to the effective prevention of irreversible accumulation of graphene sheets. However, the porous graphene macro-assemblies prepared by current methods are usually disorderly arranged in the three-dimensional (3D) space, and the aperture and porosity of which are uncontrollable, which will significantly limit its macroscopic mechanical and electric/thermal properties. This project aims at the controllable synthesis of graphene oxide and polymer template. Graphene oxide/polymer template composite membrane will be prepared by vacuum assisted filtration. Anisotropic 3D graphene porous materials with controllable distribution of pore size and porosity are obtained by the following carbonization to remove the template. Furthermore, a systematic correlation between the micro-structure and macro-electrochemical performance of the material will also be set up, so as to benefit the industrial application of graphene in advanced energy conversion and storage.

石墨烯作为的二维纳米炭材料，具有优异的物理和化学性能，应用前景十分广阔。目前将石墨烯以特定方式组装成柔性薄膜、杂化体和多孔材料等宏观体，并保持其原有纳米效应，已成为石墨烯规模化应用的有效途径。石墨烯多孔材料可有效阻止石墨烯的不可逆团聚，在能源存储与转化领域具较高应用价值。而当前方法所制石墨烯泡沫在三维空间内多为无序排列，孔径及孔隙率可控性差，限制了其宏观力学与导电/热性能的发挥。本项目旨在实现氧化石墨烯和聚合物模板剂的可控合成，通过真空过滤法制备氧化石墨烯/聚合物模板复合薄膜，再经炭化还原移除模板，制备出具有合理孔径分布、孔隙率可控、各向异性的有序石墨烯三维多孔薄膜，并构建其微观结构与电化学性能的逻辑关联，为石墨烯在储能中的低成本规模化应用奠定理论基础。

作为二维纳米炭材料，石墨烯具有优异的物理化学性能，应用前景广阔。将石墨烯以特定方式组装成柔性薄膜、杂化体和多孔材料等宏观体，并保持其原有纳米效应，已成为石墨烯规模化应用的有效途径。石墨烯多孔材料的制备可有效阻止其不可逆团聚，在能源存储与转化领域展现出极高的应用价值。而当前方法所制石墨烯泡沫在三维空间内多为无序排列，孔径及孔隙率可控性差，限制了其宏观力学与导电/热性能的发挥。本项目深入研究了氧化石墨烯的制备，实现了对氧化石墨烯官能团种类、数量的可控制备，并系统研究了粒径、交联状态和程度对三维结构的影响规律，实现了氧化石墨烯与待牺牲模板的均匀复合，结果表明片径较大的氧化石墨烯更容易用可控定向自组装的方法成膜，选择325目石墨经过改进的Hummers’ 法制备氧化石墨烯水溶胶作为原料；考察了氧化石墨烯与模板的表面化学性能对自组装过程的影响，并结合高温炭化（600 oC，800 oC，1000 oC和1200 oC）的方法移除模板，有效保留了三维有序孔状结构，对孔径分布及薄膜力学性能进行分析，结果表明，孔隙率随温度升高呈现下降趋势，综合考虑结构完整性及导电性，选择800 oC炭化后的氧化石墨烯/PS三维多孔薄膜进行后期电化学性能研究；将所制备的三维复合材料直接切成1.2 cm的电极片（无需粘结剂），成功组装成扣式电容器，串联后点亮LED，对其在柔性储能器件应用中的电化学性能进行评价，由于所制备电极材料的交联大孔结构可减少离子在孔内的传递距离，从而使得溶液中的离子可以快速进入到三维结构中与材料活性位点反应，为石墨烯在储能中的低成本规模化应用奠定理论基础。