Cao Hailiang, Peng Xing, Zhao Min, Liu Peizhi, Xu Bingshe, Guo Junjie
Key Laboratory of Interface Science and Engineering in Advanced Materials, Ministry of Education, Research Center of Advanced Materials Science and Technology, Taiyuan University of Technology Taiyuan 030024 China
Key Laboratory of Graphene Technologies and Applications of Zhejiang Province, Advanced Li-ion Battery Engineering Lab, Ningbo Institute of Materials Technology and Engineering (NIMTE), Chinese Academy of Sciences Ningbo 315201 China.
RSC Adv. 2018 Jan 12;8(6):2858-2865. doi: 10.1039/c7ra12425b.
Graphene is a promising electrode material for supercapacitors due to its superior physical and chemical properties, but the influence of its oxygen functional groups on capacitive performance still remains somewhat uncertain. In this work, graphene sheets with different oxygen content have been prepared through thermal reduction in argon. Furthermore, oxidation and pore-forming treatment of graphene annealed at 800 °C are also performed to explore the important effect of oxygen functional groups. The effects of disorder degree, surface area and oxygen functional groups on the specific capacitance were explored systematically. The content and species of oxygen functional groups are found to be significant factors influencing the electrochemical supercapacitor performance of graphene electrodes. The specific capacitances of graphene annealed at 200, 400 and 800 °C are 201, 153 and 34 F g, respectively. However, the specific capacitance of graphene reduced at 800 °C can be increased to 137 F g after nitric acid oxidation treatment, and is only 39 F g after pore forming on graphene surface, demonstrating that the oxygen functional groups can improve the capacitive performances of graphene electrochemical supercapacitors.
由于其优异的物理和化学性质，石墨烯是一种很有前景的超级电容器电极材料，但其氧官能团对电容性能的影响仍存在一定的不确定性。在这项工作中，通过在氩气中热还原制备了具有不同氧含量的石墨烯片。此外，还对在800℃退火的石墨烯进行了氧化和造孔处理，以探究氧官能团的重要作用。系统地研究了无序度、表面积和氧官能团对比电容的影响。发现氧官能团的含量和种类是影响石墨烯电极电化学超级电容器性能的重要因素。在200、400和800℃退火的石墨烯的比电容分别为201、153和34F/g。然而，800℃还原的石墨烯经硝酸氧化处理后比电容可提高到137F/g，而在石墨烯表面造孔后仅为39F/g，表明氧官能团可改善石墨烯电化学超级电容器的电容性能。
