石墨烯基气凝胶的制备及其超电容性能研究

Preparation of graphene-based aerogels and their supercapacitive performance

关键词:  超级电容器  石墨烯基气凝胶  表面官能度  电极材料  比电容

Key words:  supercapacitor  graphene-based aerogel  surface functionalized degree  electrode materials  specific capacitance

摘要:

采用氧化石墨烯自组装法制备出氧化石墨烯气凝胶(GOA),并采用高温(1100℃)氢气还原进一步制备石墨烯气凝胶(GA)。采用氮气吸附、FT-IR、元素分析和电化学测试等手段对其进行表征。结果表明:制备的两种气凝胶具有较高的BET比表面积(均约为870m²·g-1); GOA表面具有丰富的含氧官能团,GA表面氧含量极低; GOA与GA的碳氧摩尔比分别为1.7和69.9;在低电流密度下(0.2A·g-1),具有高表面官能度的GOA比电容达155.8F·g-1,而低表面官能度的GA表现出高倍率的超电容性能。

Abstract:

A self-assembly method was adopted to synthesize graphene oxide aerogel (GOA), which was further reduced by hydrogen at 1100℃ to obtain graphene aerogel (GA). Nitrogen adsorption analysis results show that both aerogels possess high BET surface areas (approximate 870m²·g-1). FT-IR analysis results reveal that the surface of GOA has more oxygen-containing groups than those of GA. Elemental results display that the C/O molar ratios of GOA and GA are 1.7and 69.9, respectively. Electrochemical measurements show that at the current density of 0.2A·g-1, the specific capacitance of GOA with high surface functionalized degree could reach up to 155.8F·g-1, while GA with low surface functionalized degree exhibits a high-rate supercapacitive performance.