石墨烯的制备及表征

为了得到高性能的石墨烯材料,采用水合肼、茶多酚与抗坏血酸3种不同的还原剂将氧化石墨烯还原制备得到石墨烯.通过红外光谱、X射线衍射、接触角对产物的结构进行表征,采用四探针法测试电导率,循环伏安法和计时电位法测试电化学性能.水合肼、茶多酚与抗坏血酸这3种还原剂都能有效地将氧化石墨烯结构中的亲水基团去除,得到疏水的石墨烯.通过比较3种还原剂制备的石墨烯的电化学性能,发现通过茶多酚还原得到的石墨烯的导电性能最好,当电流密度为3 A/g时,茶多酚还原得到的石墨烯电容性能达到609 F/g,保持率达到87.71%.这表明由茶多酚还原得到的石墨烯具有更为优良的电化学性能.

Preparation and characterization of graphene

To prepare graphene with high performance,hydrazine hydrate,tea polyphenols and ascorbic acid were used to reduce graphene oxide.The effect of the reducing agents on the properties and structures of graphene was studied.The structure of graphene was characterized by fourier transform infrared （FT-IR） spectroscopic,X-ray diffraction and contact angle measurements.Moreover,the conductivity was tested by the four-probe method and the electrochemical performance was characterized by cyclic voltammetry and chronopotentiometry.Hydrazine hydrate,tea polyphenols and ascorbic acid can remove the hydrophilic groups on graphene oxide to get hydrophobic graphene.The result shows that the conductivity of graphene reduced by tea polyphenols is the best of the three and the specific capacitance is 609 F/g at the current density of 3 A/g.The specific capacitance of graphene reduced by tea polyphenols can keep 87.71％ after 1 000 charge/discharge cycles.It indicates that graphene reduced by polyphenols has good electrochemical and recyclable properties.