中文摘要：

以天然鳞片石墨为原料,用改进的Hummers法制备氧化石墨。超声分散制备氧化石墨烯溶液,通过加入不同量的水合肼调节溶液的pH值,再通过水热法热还原,制备了在水中稳定分散的石墨烯溶液。利用扫描电子显微镜（SEM）、高分辨透射电镜（HR-TEM）、拉曼光谱（Raman）、原子力显微镜（AFM）、X射线衍射分析（XRD）、zeta电位及光学显微镜对制备的样品进行了表征,研究了不同温度、pH值对石墨烯溶液稳定性的影响。

英文摘要：

A improved Hummers method was employed to prepare graphite oxide using natural flake graphite as raw materials. The graphene oxide solution was prepared by ultrasonic dispersion, and the pH value of solution was changed through adding different volume fraction of hydrazine hydrate. After hydrothermal reduction in au- toclave, stable dispersion graphene solutions were obtained. The as prepared samples were characterized by X- ray diffraction, scanning electron microscopy, transmission electron microscopy, Raman spectroscopy, atomic force microscope, zeta potential and optical microscope. The influence of temperature and pH value of the sta- bility of graphene solutions was investigated.