掺氮多孔碳的制备及电化学性能研究

发布时间：2018-05-13 00:10

本文选题：超级电容器 + 炭微球　；参考：《湘潭大学》2017年硕士论文

【摘要】：超级电容器近些年的研究发展迅速,特别是在电极材料方面的探索十分热门。碳材料理论上是一种相对较为理想的电极材料,它具有大比表面积,较良好的导电性,高比电容,且具有制备方法简单等优点。碳材料中掺入氮元素是一种有效提升性能的方法,材料中的含氮官能团可以大幅度提高材料本身的导电性、优化孔径结构、改善表面润湿性;另外,含氮官能团可以使电极材料产生赝电容行为,因此能够提高电极材料的比电容。本论文以蔗糖和葡萄糖等廉价易得的材料做原料,通过一步水热及燃烧的处理方法对原料进行一定的改性,引入了含氮官能团以及石墨烯,最后制得了具有应用潜力的电极材料。1、本文采取改进的Hummers法制备出了氧化石墨烯(GO),并经过一系列测试方法对它的形貌和结构做了表征。同时将其作为一种强导电成分掺入到了碳微球里面,从而提高了碳球的比电容。2、采用葡萄糖(Glucose)溶液做碳源,通过一步水热反应成功制备了掺氮碳微球。通过一系列表征发现在添加g-C_3N_4量子点之后,碳微球的直径增大了15倍,且将吡啶(N-6)和吡咯/吡啶酮(N-5)形式的氮成功引入碳球。在此基础上,本文主要研究了掺入石墨烯的碳球在各项特性上的改变以及石墨烯对碳球电化学性能方面的影响。通过对比,AC-3的电化学性能相对而言比较优异,通过计算得到在2Ag~(-1),其比电容可达150Fg~(-1)。在掺入石墨烯后,碳微球的比电容相比只掺入g-C_3N_4量子点的AC-2提高了1.3倍,与单纯葡萄糖溶液制得的碳微球AC~(-1)对比提高了8.6倍。交流阻抗测试(EIS)可以很好的证明掺入石墨烯后的碳微球电阻降低,从而表明石墨烯能够增强碳微球的导电性。3、以三聚氰胺作为氮源,蔗糖(Sucrose)当做碳源,NaHCO_3作发泡剂,通过一步燃烧合成法制备了泡沫碳,然后在惰性气体中热处理后成功制备了活性多孔碳(PC)。本论文主要研究了三聚氰胺和NaHCO_3对多孔碳电性能的影响,研究了不同热处理温度对多孔碳电化学性能的影响。经研究发现三聚氰胺主要为多孔碳引入了含氮官能团,NaHCO_3主要作为活化剂优化了材料的孔径分布。经过一系列的表征得到多孔碳比表面积最高可达2084.9 m2g~(-1)。BET分析表明该材料是一种典型的微孔材料,里面有少量的介孔。电化学相关测试数据表明该材料具备较好的循环可逆性,优异的充放电效率以及导电性。在1A/g的电流密度下,PC-700的比电容可达185Fg~(-1)。
[Abstract]:Supercapacitors have developed rapidly in recent years, especially in electrode materials. Carbon material is a relatively ideal electrode material in theory, which has the advantages of large specific surface area, good conductivity, high specific capacitance and simple preparation method. The addition of nitrogen into carbon materials is an effective way to improve performance. The nitrogen-containing functional groups in the materials can greatly improve the conductivity of the materials themselves, optimize the pore structure and improve the surface wettability. The nitrogen-containing functional group can make the electrode material produce pseudo-capacitance behavior, so it can improve the specific capacitance of electrode material. In this paper, sucrose and glucose were used as raw materials, the raw materials were modified by one-step hydrothermal and combustion methods, and nitrogen-containing functional groups and graphene were introduced. Finally, the electrode material with potential application was prepared. In this paper, graphene oxide was prepared by improved Hummers method, and its morphology and structure were characterized by a series of test methods. At the same time, the carbon microspheres were doped into the carbon microspheres as a strong conductive component, thus increasing the specific capacitance of the carbon spheres. The nitrogen-doped carbon microspheres were successfully prepared by one step hydrothermal reaction using glucose Glucose solution as the carbon source. A series of characterization results show that the diameter of carbon microspheres increases by 15 times after the addition of g-C_3N_4 quantum dots, and nitrogen in the form of pyrrole N-6) and pyrrole / pyridinone N-5) is successfully introduced into the carbon spheres. On this basis, the changes of the properties of the carbon spheres doped with graphene and the effect of graphene on the electrochemical properties of the carbon spheres were studied. By comparing the electrochemical properties of AC-3, the calculated results show that the specific capacitance of AC-3 can reach 150 FG ~ (-1) ~ (-1). After the addition of graphene, the specific capacitance of carbon microspheres was 1.3 times higher than that of AC-2 with only g-C_3N_4 quantum dots, and 8.6 times higher than that of carbon microspheres prepared in glucose solution. Ac impedance test (EIS) showed that the resistance of carbon microspheres with graphene was decreased, which indicated that graphene could enhance the electrical conductivity of carbon microspheres. Melamine was used as nitrogen source, and sucrose Sucrosewas used as foaming agent for carbon source NaHCO3. The foam carbon was prepared by one step combustion synthesis method, and then the active porous carbon (PCO) was successfully prepared after heat treatment in inert gas. In this paper, the effects of melamine and NaHCO_3 on the electrochemical properties of porous carbon were studied, and the effects of different heat treatment temperature on the electrochemical properties of porous carbon were studied. It was found that melamine mainly introduced nitrogen-containing functional group NaHCOS3 into porous carbon to optimize the pore size distribution of the material as activator. The results of a series of characterization show that the maximum surface area of porous carbon is up to 2084.9 m2g~(-1).BET. The results show that the material is a typical microporous material with a small number of mesoporous materials. The electrochemical data show that the material has good cycle reversibility, excellent charge and discharge efficiency and electrical conductivity. At the current density of 1A/g, the specific capacitance of PC-700 can be up to 185Fg ~ (-1).
【学位授予单位】：湘潭大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TM53;O613.71

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