十六烷基三甲基溴化铵改进Hummers法制备石墨烯的研究

Preparation of Graphene by Hummers Method Supported by Cetyltrimethylammonium Bromide

将阳离子表面活性剂(十六烷基三甲基溴化铵,CTAB)作为絮凝剂,利用其与氧化石墨烯(GO)产生静电吸引的原理,实现中间产物CTAB-GO复合物的快速分离和纯化,并利用水合肼还原制得还原氧化石墨烯(RGO)。采用UV-Vis、SEM、TEM、AAS和XPS对石墨烯的形貌、纯度、制备过程及机理进行了分析表征。结果显示,CTAB能通过静电力吸附在GO表面,形成CTAB-GO复合物的絮凝沉淀。当CTAB和GO的质量比为1∶2时,可以达到最佳的絮凝效果。该絮凝沉淀仅通过低压过滤或低速离心(3 000 rpm,3 min)便能实现快速分离和纯化,得到CTAB-GO复合物。AAS和XPS证实CTAB-GO复合物中不存在杂质离子。此外,CTAB-GO复合物经过水合肼还原后,CTAB能快速完全脱除,从而得到高纯度RGO。

A cationic surfactant,cetyltrimethylammonium bromide(CTAB),was used as a flocculating agent for high speed separation and purification of intermediates,resulting in reduced graphene oxide(RGO).UV-Vis,SEM,TEM,AAS and XPS were used to characterize the morphology,purity,preparation process and mechanism of RGO.The results showed that CTAB can be adsorbed onto the surface of GO through ionic interactions to form a water-insoluble CTAB-GO complex.When the mass ratio of CTAB and GO was 1∶2,the best flocculation effect was achieved.CTAB-GO complex can be readily separated from the water-soluble impurities through filtration or low-speed centrifugation(3 000 rpm for 3 min).No impurity ions present in the CTAB-GO complex confirmed by AAS and XPS.More importantly,CTAB can be removed from the CTAB-GO complex by a hydrazine reduction reaction to produce pure RGO.