pH值对硫掺三维石墨烯电化学性能影响的探究

Effect of pH value on electrochemical properties of three-dimensional sulfur-doped graphene

本文以Hummers法制备的氧化石墨烯溶胶为原料,通过控制水热反应的pH值,研究了不同酸碱度对硫掺杂三维石墨烯的结构及电化学性能的影响。采用扫描电镜对其微观结构进行表征分析,结果表明硫掺三维石墨烯具有典型的石墨烯特征结构。采用循环伏安、恒电流充放电等测试手段研究了不同pH值下制备的硫掺杂石墨烯的电化学性能。结果表明,pH值越大,硫掺杂三维石墨烯的体积越大,其比容量也随pH值的增大而有明显的提升。当pH值为11时,硫掺杂三维石墨烯具有良好的电化学可逆性、较高的比容量、较好的倍率特性及良好的循环特性,在超级电容器上具有良好的应用前景。

The graphene oxide sol was fabricated with the Hummer method.The effect of the pH value of the hydrothermal reaction on the microstructure and electrochemical performance of the three-dimensional(3D)sulfur-doped graphene(SDG)was investigated.The microstructure of the SDG was revealed by scanning electron microscope(SEM).The cyclic voltammetry and the constant current charging-discharging test was applied to analyze the electrochemical properties of the 3D-SDG.The result shows that the volume and specific capacitance of 3D-SDG is obviously increased with increasing pH value.When the pH value is 11,the 3DSDP demonstrates improved electrochemical reversibility with higher specific capacitance and rate characteristics and excellent cycling performance.It is believed that this approach has a wonderful prospect in the practice of supercapacitors.