疏水石墨烯水相分散液的制备及电化学性能

通过未添加表面活性剂和稳定剂而得到均匀的石墨烯水相分散液的方法,近来来成为研究的一大热点.本工作通过提高水合肼的用量,来替代表面活性剂或者其它稳定剂的作用,得到了良好的均匀的水相石墨烯分散液,可长期稳定存放,6个月内未发生团聚现象.其Zeta电位低于-32.5 mV(pH值为5.89),原子力显微镜和透射电子显微镜图像表明产物为具有褶皱结构的、六方晶系的单层石墨烯结构,厚度为0.38 nm.XPS分析显示这种方法对于除去羟基和环氧基团起到了有效的作用.利用这种分散液所制备的石墨烯-玻碳电极(GE-GCE)在检测抗坏血酸(AA)和尿酸(UA)时,比普通玻碳电极(GCE)显示出更良好的电化学响应.

Preparation Hydrophobic Graphene Aqueous Dispersion and Electrochemical Properties

The direct dispersion of hydrophobic graphene sheets in water without the assistant of surfactant stabilizers has recently been recognized as an important task for production of individual graphene sheets.We developed a facial method to disperse hydrophobic graphene sheets in aqueous medium through enlarging the amount of hydrazine-hydrate in the absence of surfactant or any other foreign electrostatic stabilization agents.Homogeneous aqueous graphene dispersion had produced lower zeta potential of more negative than-32.5 mV at solution pH of 5.89 and was stable for six months without any precipitate.The folded individual single-layer graphene sheets with 0.38 nm layer thick and the formation of a hexagonal crystalline graphene structure were observed from AFM and TEM images,respectively.XPS analysis showed the efficient reduction of graphene oxide.As-prepared graphene-glassy carbon electrode(GE-GCE) showed a relatively sensitive electrochemical response toward the detection of AA and UA than glassy carbon electrode(GCE).