水热反应温度对三维还原氧化石墨烯的形貌、结构和超级电容性能的影响

发布时间：2018-08-09 10:49

【摘要】：以氧化石墨凝胶制备的氧化石墨烯溶胶为前驱体,在120-220°C条件下,采用水热法制备了系列不同还原程度的三维还原氧化石墨烯,采用扫描电镜(SEM),X射线衍射(XRD),傅里叶变换红外(FTIR)光谱,X射线光电子能谱(XPS)和电化学测试等手段研究了水热反应温度对材料形貌、结构和超级电容性能的影响.结果表明:采用水热法制备的三维还原氧化石墨烯呈多孔网状结构,材料的体积和内部网状孔径随着水热反应温度的升高而减小;同时,氧化石墨烯的还原程度随反应温度的升高而增加,有序度提高,其结构逐渐向着类石墨结构转化;而材料的比电容和能量密度则随反应温度的升高呈现出先增大后减小的趋势,且均以双电层电容为主;相比之下,当水热反应温度为180°C时,制备的三维还原氧化石墨烯具有最佳的超级电容性能,在电解液为6mol·L-1的KOH溶液中,0.5A·g-1电流密度下其比电容达到315 F·g-1,10 A·g-1时仍能保持212 F·g-1的高比容量,能量密度为40.5Wh·kg-1,5000次循环后比电容保持率为86%,表现出了良好的电化学性能.
[Abstract]:Using graphene oxide sol prepared by graphite oxide gel as precursor, a series of three dimensional reductive graphene oxide was prepared by hydrothermal method under the condition of 120-220 掳C. The effects of hydrothermal reaction temperature on the morphology, structure and supercapacitor properties of the materials were investigated by means of scanning electron microscope (SEM), (SEM) X-ray diffraction (SEM), (XRD), Fourier transform infrared (FTIR) spectroscopy, X-ray photoelectron spectroscopy (XPS) and electrochemical measurements. The results show that the three-dimensional reductive graphene prepared by hydrothermal method has a porous reticular structure, and the volume and internal reticular pore size decrease with the increase of hydrothermal reaction temperature, at the same time, The reduction degree of graphene oxide increases with the increase of reaction temperature, and the order degree increases, and the structure of graphite-like structure gradually changes to graphite-like structure, while the specific capacitance and energy density of the materials increase first and then decrease with the increase of reaction temperature. In contrast, when the hydrothermal reaction temperature is 180 掳C, the three dimensional reductive graphene has the best super capacitor performance. Under the current density of 0.5A g ~ (-1) in KOH solution with 6mol L-1, the specific capacitance of 212F g ~ (-1) can be maintained at 315F g ~ (-1) ~ (10) A g ~ (-1), and the specific capacitance retention rate of 212F g ~ (-1) is 86 after the energy density is 40.5Wh kg-15 000 cycles, showing good electrochemical performance.
【作者单位】：西南科技大学材料科学与工程学院;西南科技大学分析测试中心;西南科技大学矿物材料及应用研究所;
【基金】：国家自然科学基金(41272051) 西南科技大学博士基金(11ZX7135) 西南科技大学研究生创新基金(14ycx003)资助项目~~
【分类号】：TM53

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