【摘要】 本研究以氧化石墨烯（GO）为柔性基底,硫脲为硫氮源,碳点（CDs）为插层剂,采用水热和煅烧两步法合成碳点/硫氮共掺杂石墨烯气凝胶（CDs/SNGA）复合材料。通过X射线衍射（XRD）、紫外可见光（UV-vis）和透射电镜（TEM）测试分析证实CDs具有类石墨结构,其粒径2～4 nm。将其插入到石墨烯片层后,扫描电镜（SEM）显示CDs/SNGA复合材料孔道结构更加丰富,缓解了石墨烯片层的堆积。电化学性能结果显示,CDs/SNGA可逆比容量可达229.98 m A·h·g^-1 (在5 A·g^-1电流密度下),明显优于硫氮共掺杂石墨烯气凝胶(SNGA,73.60 m A·h·g^-1)和石墨烯气凝胶(GA,48.33 m A·h·g^-1)。另外,在1 A·g^-1电流密度条件下循环300圈后,CDs/SNGA仍可以维持489.3 m A·h·g^-1的可逆比容量,相对于SNGA(195.1 m A·h·g^-1)和GA(173.2 m A·h·g^-1)分别提升1.5倍和1.8倍。更多还原

【Abstract】 In this paper, carbon dots/sulfur-nitrogen co-doped graphene aerogel（CDs/SNGA） composites were synthesized by a two-step hydrothermal and calcination method using graphene oxide（GO） as a flexible substrate,thiourea as a sulfur-nitrogen source and carbon dots（CDs） as an intercalator. Firstly, the results of X-ray diffraction（XRD）, ultraviolet-visible（UV-vis） and Transmission electron microscope（TEM） tests confirmed the successful synthesis of CDs with graphite-like structure and particle size of about 2-4 nm. After their insertion into graphene lamellae, SEM showed that the pore structure of CDs/SNGA composites was more abundant and alleviated the accumulation of graphene lamellae. Secondly, according to the electrochemical performance results, the reversible specific capacity of CDs/SNGA can reach about 229. 98 m A·h ·g^-1at 5 A· g^-1current density, which was significantly better than that of sulfur-nitrogen co-doped graphene aerogel( SNGA, 73. 60 m A · h · g^-1) and graphene aerogel(GA, 48. 33 m A·h·g^-1). In addition, after 300 cycles at 1 A·g^-1current density, CDs/SNGA can still maintain a reversible specific capacity of 489. 3 m A·h·g^-1. Compared with SNGA(195. 1 m A·h·g^-1)and GA(173. 2 m A·h·g^-1), the increase is 1. 5 times and 1. 8 times respectively.更多还原