甲基橙修饰石墨烯的制备及电容性能

Preparation and capacitive properties of methyl orange modified graphene

为了改善石墨烯的分散性和提高石墨烯的比电容,采用非共价键表面修饰方法 ,在氧化石墨烯还原过程中加入甲基橙,利用甲基橙与石墨烯的π-π相互作用,将甲基橙接枝在石墨烯的表面,成功地制备了甲基橙接枝石墨烯.采用傅里叶变换红外光谱(FTIR)、场发射扫描电子显微镜(FESEM)及电化学工作站,对改性石墨烯的组成、结构及电化学性能进行了测试.FTIR测试证实了甲基橙成功地接枝到石墨烯的表面,FESEM显示改性石墨烯片层剥离比较好;水溶性测试显示与未改性的石墨烯相比,甲基橙改性的石墨烯在水中具有良好的分散性.电化学循环伏安法显示改性石墨烯作为电极材料具有良好的电容倍率特性,而且恒电流充放电测试也显示了当电流密度为0.15 A/g时,改性石墨烯的比电容达到101 F/g.

To improve the dispersion of graphene and enhance specific capacitance of graphene, methyl orange(MO) was successfully grafted on the surface of graphene via strong π-π interaction between graphene and MO in reaction system during the reduction process of graphene oxide with non-covalent surface modification method. The composition, structure and electrochemical properties of the modified graphene were tested with infrared spectroscopy(FTIR), field emission scanning electron microscopy(FESEM) and electrochemical workstation. FTIR confirms that methyl orange successfully graft onto the surface of grapheme, and FESEM shows the modified graphene exists in single layer or few layers. Water-solubility test shows the methyl orange modified graphene has better dispersion compared to the unmodified graphene in water. Cyclic voltammetry shows the modified graphene as electrode material has a good rate capability. And constant current charge-discharge test shows that the specific capacitance of modified graphene can reach 101 F / g when the current density is 0.15 A / g.