摘要石墨烯具有大的比表面积和良好的导电性，氮化碳具有丰富的氮含量，电子亲和能大的氮原子可以有效地调剂石墨烯表面碳原子的自旋密度和π电子分布，通过氮化碳对石墨烯进行表面改性，并将其制备成为水凝胶，不仅有利于提高石墨烯的双电层电容，还可有效减少石墨烯片层之间的团聚。本论文采用水热合成法，以单片层的氧化石墨及氮化碳为原料，水合肼为还原剂，在氨水的碱性环境中成功制备出石墨烯/氮化碳复合物水凝胶，利用XRD、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，掺杂比例为7:3的石墨烯/氮化碳具有最高的比容量，同时倍率性能卓越，在大电流充放电的条件下任然可以保持较高的比容量，循环性能稳定，循环5000圈后任然可以保持95%的比容量。68450

毕业论文关键词  石墨烯  氮化碳  水凝胶  超级电容器     

毕业设计说明书（论文）外文摘要

Title   The Synthesis of the g-C3N4 modified Graphene Hydrogels and their electrochemical properties 

Abstract

Graphene has a large specific surface area and a good electrical conductivity, while the graphic carbon nitride is an analogue of graphite, which possesses a stacked 2D structure. nitrogen atoms in the g-C¬3N4 layers can influence the spin density and charge distribution of neighbor carbon atoms on the surface of graphene and activate them, which makes the g-C3N4/graphene materials maintain acceptable conductivity and considerable electric double layers. The g-C3N4 and graphene could be combined in the form of hydrogel, By this way; the specific capacitance could be significantly inproved and the obtained 3D structure could effectively reduce the restacking of the graphene and g-C3N4 sheets. In this paper, one step hydrothermal method was used to prepare g-C3N4/graphene hydrogel with the graphite oxide and g-C3N4 as the raw material and hydrazine hydrate as reducing agent in the alkaline environment of the ammonia. The g-C3N4/graphene hydrogel was successfully prepared, which was also characterized by XRD, SEM, FT-IR and Raman, and its electrochemical properties were studied as well. The results showed that the obtained g-C3N4/graphene exhibits highest electrochemical performance when the raw materials mass ratio is 7:3. 

Keywords  Graphene  Carbon nitride  Hydrogel   Supercapacitor   

目   次

1 引言 1

1.1 超级电容器 1

1.2 石墨烯 4

1.3 石墨相氮化碳 8

1.4 本论文的工作 11

2 实验试剂及仪器 12

2.1 试剂 12

2.2 仪器 12

3 氧化石墨的制备和表征 14

3.1 氧化石墨的制备 14

3.2 氧化石墨的结构表征 14

4 石墨相氮化碳的制备和表征 16

4.1 石墨相氮化碳的制备 16

4.2 石墨相氮化碳的结构表征 16

5 氮化碳/石墨烯复合水凝胶的制备和表征 18

5.1 氮化碳/石墨烯复合水凝胶的制备 18

5.2 氮化碳/石墨烯复合水凝胶的结构表征 19