Graphene-based nitrogen self-doped hierarchical porous carbon aerogels derived from chitosan for high performance supercapacitors
Graphene-based nitrogen self-doped hierarchical porous carbon aerogels derived from chitosan for high performance supercapacitors
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DOI：
10.1016/j.nanoen.2015.02.035
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发表时间：
2015-07-01
期刊：
影响因子：
17.6
通讯作者：
Yang, Bin
中科院分区：
文献类型：
--
作者：
Hao, Pin;Zhao, Zhenhuan;Yang, Bin
以壳聚糖为原料，通过严格控制气凝胶形成-炭化-活化过程，合成了超级电容器电极用石墨烯基氮气自掺杂层状多孔炭气凝胶。用透射电子显微镜、扫描电子显微镜、比表面积法等手段证实了合成的含氮石墨烯基炭气凝胶中既有气凝胶制备和炭化过程中的大孔和中孔，也有化学活化后的微孔。由于壳聚糖是一种含氮可再生生物聚合物，因此本论文合成的壳聚糖碳气凝胶是N自掺杂的。碳化碳气凝胶由石墨烯骨架和无定形碳组成，两者的比例由活化温度控制。随着活化温度的升高，无定形碳逐渐被腐蚀掉，而稳定的石墨烯部分形成了骨架。因此，石墨烯基碳气凝胶作为超级电容器的性能随活化温度的升高而变化。电化学测试表明，N掺杂石墨烯基多孔炭气凝胶是构建固体对称超级电容器的良好电极候选材料，在0.2Ag(-1)的电流密度下表现出约197Fg(-1)的高比电容。此外，固态超级电容器表现出极佳的性能
Graphene-based nitrogen self-doped hierarchical porous carbon aerogels were synthesized for supercapacitor electrode application by using chitosan as a raw material through a carefully controlled aerogel formation-carbonization-activation process. The as-synthesized N-doped graphene-based carbon aerogels contained both macropores and mesopores from the aerogel preparation and carbonization process, and micropores from the chemical activation, confirmed by TEM, SEM, BET, etc. Because chitosan is a nitrogen-containing renewable biopolymer, the carbon aerogel derived from chitosan in this work was N-self -doped. The carbonized carbon aerogel was composed of a graphene framework and amorphous carbon, and the ratio between these two components was controlled by the activation temperature. With an increase in activation temperature, the amorphous carbon was etched away gradually, and a stable graphene portion remained to form a framework. Accordingly, the performance of the graphene-based carbon aerogel as a supercapacitor varied with increasing activation temperature. Electrochemical investigation measurements showed that the N-doped graphene-based hierarchical porous carbon aerogel represents a good electrode candidate for construction of a solid symmetric supercapacitor, which displays a high specific capacitance of about 197 F g(-1) at a current density of 0.2 A g(-1). In addition, the solid state supercapacitor displayed excellent