Nafion改性多级孔径石墨烯气凝胶制备与性能研究

通过溶胶-凝胶法制备了孔径小于1 μm的多级孔径新型石墨烯气凝胶。制备过程中, 首先通过Nafion对氧化石墨烯(GO)表面进行化学修饰, 并利用乙二胺还原制备石墨烯水凝胶, 最终通过冷冻干燥形成石墨烯气凝胶。实验发现Nafion可以有效减少制备过程中氧化石墨烯的团聚, 使石墨烯气凝胶形成多级孔径形貌。所得石墨烯气凝胶的孔径可控制在1 μm以内, 远小于传统石墨烯气凝胶材料的孔径(20~100 μm)。这种具有独特结构的石墨烯气凝胶表现出优异的性能, 例如高比表面积, 高孔隙率, 其电化学电容性能相对传统气凝胶提高了约40%。

Nafion Modified Graphene Aerogel with Hierarchical Porous Structures

A novel graphene aerogel with pore size less than 1 µm was synthesized by Sol-Gel method, in which Nafion was skillfully introduced as modifiers connecting graphene oxides (GO). Ethylenediamine was used to produce a chemically linked graphene hydrogel during reducing process, which can then be freeze-dried to remove the absorbed water to form graphene aerogel. Nafion in GO solution prohibits the re-stacking of individual graphene sheets during reduction and freeze-drying process. By the above method, the pore size of as-prepared graphene aerogel could be effectively controlled within 1 µm, much less than that of the traditional graphene aerogel (20- 100 µm). The new graphene aerogel with unique structure exhibited excellent properties, such as high specific surface area, high porosity, and better electrochemical properties. All data suggest that this graphene aerogel may have promising application prospect in the field of energy.