基于共价交联策略设计和构筑多功能石墨烯气凝胶的结构与性能

Graphene aerogels, with the combination of two-dimensional structure and three dimensional structure, show many extraordinary properties, such as ultra-low density, high porosity, as well as the high excellent surface utilization and good operability. Controllable assembly of the building blocks is essential for the preparation of graphene aerogels. This project proposes the idea of covalent cross-link between the epoxy groups on the basal plane of graphene oxides and the diamines, which facilitates the preparation of graphene aerogels with pillared molecules between the graphene sheets. We focus on the development of a rapid and facile method for the construction of graphene aerogels with controlled structures in large scale and clarify the mechanisms taking place during the cross-link reaction and the assembly of graphene sheets in the solvent. Selective reduction will be realized by using the Pickering emulsion of graphene oxide (GO) to give graphene aerogels with unique Janus structure. Metal organic frameworks (MOF) are grown in the Janua reactor with confined space. The growth and conversion of the ZIF-67 will give the carbon nanotubes/graphene hybrid aerogels. The aerogel composites with excellent mechanical properties and novel structures will be achieved. The relationships between the compositions, the structures and the properties of the aerogel composites will be clarified. The implementation of the project will develop new methodology for the preparation of multifunctional graphene aerogels with high performance in electrochemical energy storage as well as environmental remediation, therefore, it has both theoretical and practical significance for the development of new technique with intellectual property right.

石墨烯气凝胶融合了二维石墨烯片状结构以及三维立体结构的共同结构特征，具有孔隙率高、密度低以及应用范围广等优点。申请课题基于氧化石墨烯（GO）基面环氧基开环共价交联反应形成的分子柱撑调控石墨烯片层间的面间距离；通过制备GO的Pickering乳液，在油水两相界面控制GO组装和选择性还原，实现对石墨烯气凝胶层片面间距离、孔泡尺度、表面化学组成的精确调控，合成具有Janus结构特征的石墨烯气凝胶反应器，研究石墨烯气凝胶Janus反应器内ZIF-67成核、限域生长过程以及转化机制，构建石墨烯/氮掺杂碳纳米管多功能复合气凝胶。开发力学强度优良、组成和结构新颖的多功能石墨烯气凝胶复合体系构建新方法，揭示石墨烯气凝胶的组成、结构与其性能之间的构效关系。课题的实施可实现石墨烯及其复合气凝胶的可控制备，对于开发具有自主知识产权的高性能电化学储能材料以及环境污染修复材料具有重要的理论和现实意义。

项目实施过程取得以下结果：（1）基于共价交联策略构建超高弹性三维石墨烯气凝胶压力传感材料。通过聚醚胺与氧化石墨烯表面含氧官能团环氧基的开环共价交联，制备得到三维氧化石墨烯泡沫材料，温和热还原脱除氧化石墨烯表面含氧官能团，得到的共价交联石墨烯泡沫具有良好的压缩性和导电性，共价交联的石墨烯泡沫在不同的压缩应变下具有可调的电导率和超灵敏的压力响应 (在3.5-5 kPa范围内压力灵敏度为0.046 kPa-1)，在弹性导电材料和超灵敏压力传感领域具有应用前景；(2)采用碳纳米管液相氧化开壁技术制备氧化石墨烯纳米带，以氧化石墨烯纳米带为前驱体、Pickering乳液为模板、聚醚胺为助剂和交联剂，制备孔径均匀可控的石墨烯纳米带气凝胶。所得石墨烯纳米带气凝胶具有均匀的孔结构和优异的可压缩性能，高压缩形变下（95%）石墨烯纳米带气凝胶仍可恢复原状，气凝胶的电阻与形变之间有良好的线性对应关系，且与压缩速率无关，制备的石墨烯纳米带气凝胶在能量缓冲、电化学储能和环境保护等方面具有应用潜能；(3) 高活性和高稳定性的石墨烯复合型气凝胶构建及其三维电极氧化消除废水有机物。通过结合表面活性剂辅助、亚铁离子原位还原和冷冻干燥等技术，制备FeOOH/石墨烯复合气凝胶，以其构建三维电极废水处理体系，通过电芬顿反应高效氧化消除污水中的有机物，有效提高了三维电极对废水有机物的氧化消除能力；(4)多级孔道三维碳材料构建及其电化学储能应用。通过化学发泡与原位活化、纳米碳材料与活性物质耦合等技术，构建了多级孔道、高比表面积的三维碳骨架及其复合材料，材料展示出良好的电化学性能，制备的复合型三维碳材料在超级电容器以及新型电池等方面展现出应用前景；