三维石墨烯的制备及其影响因素

Preparation and Influencing Factors of the 3-D Graphene

采用绿色还原剂L-抗坏血酸还原氧化石墨烯(GO),在常压、较低的温度下快速制备三维石墨烯。通过对反应物GO质量浓度和还原剂质量的比较以及对反应过程的实时监控,发现二者与三维石墨烯的形成密切相关。当GO质量浓度和L-抗坏血酸的质量浓度较低时,由于反应速率慢导致石墨烯无法形成稳定的三维结构。只有增大GO质量浓度和L-抗坏血酸的质量浓度、加快反应速率才能形成三维微孔结构石墨烯。通过冷冻干燥形成的石墨烯气凝胶具有优异的机械强度。比较SEM图可知,GO的质量浓度与三维石墨烯的内部形貌存在一定关联,可以通过控制GO质量浓度以及L-抗坏血酸的量制备不同形貌的三维石墨烯。

3-D graphene was prepared rapidly by reducing the graphene oxide （GO） with the green reducing agent L-ascorbic acid at normal pressure and low temperature. This is a simple, quick and environment friendly method. By the comparison of the mass concentration of the reactant GO and the mass of the reducing agent, and the real time monitoring of the reaction process, it is found that the mass concentration of the GO and the dosage of L-ascorbic acid are intimately related to the formation of the 3-D graphene. Due to the lower reaction rate, the 3-D graphene is not easy to be formed at low mass concentrations of the GO and L-ascorbic acid. Therefore the 3-D graphene with the micropore structure can be formed by increasing the mass concentrations of the GO and L-ascorbic acid, and accelerating the reaction rate. By freeze-drying method, the prepared graphene aerogel will have excellent mechanical strength. It is found that the morphology of the 3-D graphene is relevant to the mass concentration of the GO by comparing the SEM images. Different morphologies of the 3-D graphene can be prepared by controlling the GO mass concentration and the amount of L-ascorbic acid.