一步法制备三维还原氧化石墨烯/NiO超级电容器电极材料及其性能研究

本研究以氧化石墨烯分散液(GO)和硝酸镍(Ni(NO₃)₂·6H₂O)为前驱体, 通过一步水热法制备自支撑三维还原氧化石墨烯/NiO复合电极材料(3D rGO/NiO)。用XRD和SEM等分析结果表明, 纳米NiO颗粒均匀分散在三维多孔石墨烯表面。当GO与Ni(NO₃)₂·6H₂O质量比为1 : 4时, 3D rGO/NiO在电流密度为1 A·g^-1 下比电容可达1208.8 F·g^-1; 当电流密度从0.2 A·g^-1增加到10 A·g^-1时, 复合电极材料电容保持率高于72.6%; 在电流密度为10 A·g^-1下进行恒流充放电循环测试10000次后, 其比电容仍然保持为初始比电容的93%, 表明该复合电极材料具有良好的倍率性能和循环稳定性能。3D rGO/NiO复合电极材料具有比纯NiO或rGO更优异的电化学性能。

One-step Preparation and Electrochemical Performance of 3D Reduced Graphene Oxide/NiO as Supercapacitor Electrodes Materials

In this study, by using dispersions of graphene oxide (GO) and nickel nitrate (Ni(NO₃)₂·6H₂O) with different ratios as precursors, three-dimensional self-supported reduced graphene oxide/NiO composites (3D rGO/NiO) were prepared via a one-step hydrothermal method. The analysis results (XRD, SEM, etc) indicate that NiO nanoparticles are homogeneously dispersed on the surface of graphene layers. The specific capacitance of 3D rGO/NiO composite reaches 1208.8 F·g^-1 at a current density of 1 A·g^-1 when the mass ratio of GO and Ni(NO₃)₂·6H₂O is 1 : 4. With the current density increasing from 0.2 to 10 A·g^-1, the specific capacitance retention of this composite is higher than 72.6%. After 10000 cycles, the specific capacitance of 3D rGO/NiO at a current density of 10 A·g^-1 remained at 93% of the initial specific capacitance. All of these demonstrated that the composite possesses good rate capability and cycle stability. The 3D rGO/NiO composite has excellent electrochemical performances when compared with pure NiO or rGO, which is attributed to the synergistic effect between NiO and rGO.