RuO2/石墨烯纳米复合材料的合成及其电化学性能

摘要

通过水热反应和高温焙烧方法制备了负载RuO2纳米粒子的石墨烯纳米复合材料(RuO2/G).利用 X射线衍射(XRD)、扫描电子显微镜(SEM)、透射电子显微镜(TEM)、热重分析(TGA)和 X 射线光电子能谱(XPS)对材料的结构和形貌进行了表征.结果表明,在复合材料中,平均粒径为3.6 nm的RuO2纳米粒子均匀地负载在石墨烯片层上.该材料作为超级电容器的电极材料,表现出了良好的电容性能.当 RuO2的质量分数为35%时,在6 mol/L KOH 电解液中,复合材料的比电容为402.5 F/g,且表现出了较高的能量密度(14 Wh/kg)和功率密度(50 W/kg).该复合材料体现了石墨烯双电层电容和RuO2赝电容的性质,为性能优异的储能材料.%RuO2/graphene (RuO2/G)composites were synthesized through a hydrothermal reaction and followed by an annealing process.The structure and morphology of the materials were characterized by X-ray diffraction (XRD),scanning electron microscope (SEM),transmission electron microscopy (TEM),thermogravimetric analysis (TGA)and X-ray photoelectron spectroscopy (XPS).The results show that RuO2 nanoparticles with average size of 3.6 nm are homogeneously deposited on the surface of the graphene sheets.As an electrode mate-rial,RuO2/G exhibits an excellent supercapacitive behavior.Electrochemical performance of the materials was evaluated by cyclic voltammetry (CV),galvanostatic charge-discharge and electrochemical impedance spectros-copy (EIS).With 35wt% RuO2 loading,RuO2/G shows a specific capacitance of 402.5 F/g in 6 mol/L KOH electrolyte.Meanwhile,the electrode material also delivers a high energy density of 1 4 Wh/kg and power densi-ty of 50 W/kg in aqueous electrolyte system.Moreover,the RuO2/G material exhibits good rate performance and cycle stability.Utilizing the double-layer capacitance of graphene and the pseudocapacitance of RuO2, RuO2/G composite is an ideal electrode material for the energy storage device.