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摘要石墨烯具有大的比表面积和良好的导电性，将其制备成为水凝胶，可有效减少石墨烯片层的团聚。本论文采用氧化-还原法，以氧化石墨为原料、水合肼为还原剂，在氨水的碱性环境中成功制备出石墨烯水凝胶，利用SEM、FT-IR和Raman对样品进行了结构表征，并对其进行了电化学研究。结果表明，制备出的石墨烯水凝胶具备褶皱的片状结构。温度对样品的电化学性能影响较大，随着温度升高，样品的比电容减小，最大比电容值为146.8F/g。原料经冰冻和解冻可使制备出的样品褶皱度获得一定程度的增加，但对比电容的贡献不大。凝胶烘干后，由于比表面积和孔体积的减小，电化学性能大幅下降。关键词 石墨烯 水凝胶 超级电容器 电化学性能9356
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毕业设计说明书（论文）外文摘要
Title The Structural Control of the Graphene Hydrogels and their properties
Abstract
Graphene has a large specific surface area and a good electrical conductivity, which could be prepared in the form of hydrogel to reduce the restacking of the graphene sheets effectively. In this paper, oxidation-reduction method was used to prepare graphene hydrogel with graphite oxide as the raw material and hydrazine hydrate as reducing agent in the alkaline environment of the ammonia. The graphene hydrogel was successfully prepared, which was also characterized by SEM, FT-IR and Raman, and its electrochemical properties were studied as well. The results showed that the obtained graphene hydrogel has the fold-sheet structure. The temperature has a great influence on the electrochemical properties of the samples, and the capacitances of the samples decrease with the increasing temperature. The maximum specific capacitance value is 146.8F/g. Graphite oxide, which was frozen and thawed, could increase the corrugation degree of the graphene sheets to some extent, but this didn't make a great difference to the specific capacitance of the samples. The electrochemical performance of the dried gel dropped significantly because of the decreasing surface area and pore volume.
Keywords Graphene Hydrogel Supercapacitor Electrochemical Performance
目 次
1 引言 1
1.1 石墨烯 1
1.2 氧化石墨烯 4
1.3 石墨烯的应用 5
1.4 本论文的工作 8
2 实验部分 10
2.1 药品与仪器 10
2.2 石墨烯水凝胶的制备 10
2.3 结果与讨论 12
3 石墨烯水凝胶电容性能研究 15
3.1 GO是否冰冻制得的SGH电化学性能的比较 15
3.2 不同温度制得的SGH电化学性能比较 19
3.3 干凝胶与水凝胶电化学性能比较 23
结 论 25
致 谢 26
参 考 文 献 27
1 引言
2004年Geim等[1]使用微机械剥离法成功地将石墨层片剥离，观察到单层的石墨片层，这种单独存在的二文有序碳被科学家们称为石墨烯。
石墨烯是单层原子厚度的石墨，具有二文蜂窝状网格结构，是目前发现的唯一存在的二文自由态原子晶体。它是构筑sp2杂化碳的基本结构单元（如图1-1所示）：零文富勒烯是由石墨烯包裹而成；一文碳纳米管是由石墨烯卷曲而成；三文石墨是有石墨烯一层一层堆积而成。
图1-1 石墨烯演变成C60、碳纳米管和石墨的示意图[2]
自从石墨烯被成功制备出来以后，石墨烯在全世界范围内掀起了一股新的研究热潮，各种极具魅力的奇特性质相继被发现，预测其很有可能会在很多领域引起革命性的变化。石墨烯具有独特的结构和优异的电学、热学、力学等性能，这些优异得性能使其得以在包括电极材料、能源转化储存领域、复合材料、场发射材料和高灵敏度传感器等诸多领域中发挥巨大的作用[3]。