石墨烯的化学插层法制备及其在超级电容器中的应用

发布时间：2018-04-23 03:24

  本文选题：石墨烯 + 化学插层法　； 参考：《兰州理工大学》2014年硕士论文

【摘要】：石墨烯是一种新型二维炭材料,其诸多优异的理化性质引起世界各国的广泛关注,科学家们发现石墨烯在微纳电子器件、高灵敏传感器、功能复合材料、储能、催化等领域有着非常广阔的应用前景。然而,石墨烯功能材料尚未走进寻常百姓生活,一个主要原因是当前尚未能实现高质量石墨烯的宏量制备。化学插层法具有工艺简单、条件温和以及产品结构缺陷少等显著特点,这些优势天然地有利于实现石墨烯的宏量制备；超级电容器是一种性能介于二次电池和传统电容器之间的新型储能装置,具有比二次电池更高的功率密度,比传统电容器更高的能量密度。超级电容器因其功率密度高、循环寿命长、工作温度范围宽、绿色环保无污染等优点受到广泛关注,石墨烯超大的比表面积、良好的导电性以及机械强度等优点,在超级电容器领域显示出巨大的潜力：本文以此作为切入点,一方面以成本低廉、工艺简单、产品高品质为技术要求设计新的石墨烯制备方法,另一方面以石墨烯作为超级电容器电极材料,研究比较哪些因素对超级电容器性能的影响是主要的哪些是次要的。取得的主要成果包括： 一、设计了一种改进的化学插层法,以(NH4)2S2O8、H2SO4和H2O2为原料,实现了常温下天然石墨在插层反应的同时进行充分地膨胀,省去了当前化学插层法中800℃以上高温或微波辐照这一必要条件,从而降低了成本,简化了工艺。经表征,制得的石墨烯具有良好的品质。 二、基于化学插层法基本原理,提出“分子铲”剥离制备法,即先将天然石墨通过混酸法制成酸插层石墨(也叫可膨胀石墨),利用苄胺分子上显碱性的氨基与酸插层石墨层间的酸性基团由于酸碱中和而形成的“趋向力”,尺寸较大的苄胺分子就像“铲子”一样将石墨一层层“铲开”得到石墨烯片。再将其分散到DMF中用真空抽滤法制成石墨烯透明导电膜,经酸处理和空气中退火后,测得其在80%透光度条件下方块电阻值最低能达到350Ω/sq。 三、通过改进的Hummer法制备氧化石墨烯,在不同温度的氩气中还原得到一系列热还原氧化石墨烯(T-RGO),将其作为超级电容器电极材料。运用电化学分析测试手段比较了比表面积、材料导电性和表面含氧官能团三个因素对电容性能影响的大小结果表明,石墨烯表面含氧官能团对其电容性能的影响要远大于导电性和比表面积的影响。这使我们以后在设计制备超级电容器等储能设备用石墨烯电极材料时更加有针对性。
[Abstract]:Graphene is a new two-dimensional carbon material, and its excellent physical and chemical properties have attracted worldwide attention. Scientists have found graphene in micro and nano electronic devices, high sensitivity sensors, functional composites, energy storage. Catalysis and other fields have a very broad application prospects. However, graphene functional materials have not yet entered the lives of ordinary people, one of the main reasons is that the high quality graphene macroscopical preparation has not been realized yet. The chemical intercalation method is characterized by simple process, mild conditions and less defects in the product structure. These advantages are naturally beneficial to the macrosynthesis of graphene. Supercapacitor is a new type of energy storage device with performance between secondary battery and conventional capacitor. It has higher power density than secondary battery and higher energy density than traditional capacitor. Because of its high power density, long cycle life, wide range of working temperature, environmental protection and no pollution, super capacitor has many advantages, such as large specific surface area of graphene, good electrical conductivity and mechanical strength, etc. It shows great potential in the field of supercapacitors. On the one hand, a new preparation method of graphene is designed according to the requirements of low cost, simple process and high quality of products. On the other hand, graphene is used as electrode material of supercapacitor to study which factors affect the performance of supercapacitor. The main results achieved include: Firstly, an improved chemical intercalation method was designed, using NH _ 4N _ 2S _ 2O _ 8 H _ 2SO _ 4 and H2O2 as raw materials, the natural graphite was fully expanded at room temperature while intercalation reaction. The necessary condition of high temperature above 800 鈩，

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