石墨烯/碳纳米管的制备及其超级电容性能

Preparation of graphene/CNT and performance of supercapacitor

首先采用改性Hummers法制备氧化石墨(GO),然后以乙二醇为溶剂、水合肼为还原剂,采用化学还原法并结合冷冻干燥,制备石墨烯/碳纳米管(Gr/CNT)复合材料。研究了CNT添加量对Gr的结构及超级电容性能的影响。结果表明,适量CNT的添加会使Gr变得更加蓬松,但过量CNT的加入又会起到反作用。随着CNT和GO的质量比从0增加到0.4∶1.0,Gr/CNT材料的比电容呈先增加后降低的趋势,在CNT和GO的质量比为0.3∶1.0时比电容达到最大值。Gr/CNT-0.3复合材料在0.1 A/g电流密度下的比电容为104.8 F/g,是Gr材料的1.5倍,并具有良好的稳定性。

Graphite oxide (GO) was prepared by using modified hummers method. And then graphene/carbon nanotube (Gr/CNT) composites were prepared via chemical reduction method combining freeze drying with ethylene glycol as solvent and hydrazine hydrate as reducing agent. The effects of CNT addition on the structure and supercapacitive property of Gr were studied. The results show that the appropriate addition of CNT can make the Gr fluffier and lead to improved supercapacitive property, but the excessive addition of CNT to Gr can result in performance degradation. As the CNT/GO mass ratio increases from 0 to 0.4∶1.0, the specific capacitance of Gr/CNT increases at the beginning and then decreases. The Gr/CNT composites exhibit maximal specific capacitance when CNT/GO mass ratio is 0.3∶1.0. The specific capacitance of Gr/CNT-0.3 at 0.1 A/g is 104.8 F/g, which is 1.5 times as high as that of Gr. In addition, Gr/CNT-0.3 composites has good stability.