超重力氧化还原法制备石墨烯的研究

发布时间：2018-04-12 17:51

本文选题：旋转填料床 + 剥离　；参考：《北京化工大学》2015年硕士论文

【摘要】：石墨烯,基于其二维蜂窝状单原子层结构,在力学、热学、光学以及电学领域展现了杰出的特性,掀起了众多科研学者对其基础以及应用领域的研究热潮,包括超级电容器、传感器、太阳能电池等。本文研究了超重力旋转填料床制备石墨烯过程中不同因素对其结构和性能影响,建立了可控规模化制备高性能石墨烯的新方法,并与常规的超声剥离、机械搅拌还原法对比分析。研究结果表明：(1)氧化石墨剥离过程的影响因素中,旋转填料床的填料填充体积对制备的氧化石墨烯影响最为显著,其次是剥离时间、氧化石墨悬浮液浓度及转子速度。研究分析各因素下不同条件制备的氧化石墨烯结构,选择最适的条件配比可制备出片层面积6μm2以上的双层氧化石墨烯,比表面积可达到735 m2·g-1左右。超重力法剥离的浓度为1.5mg·mL-1,比剥离浓度范围在0.1～1.0 mg·mL-1的超声剥离法要高。通过添加辅助试剂或采用旋转填料床与超声装置联合对剥离过程进行优化,能够将氧化石墨烯的比表面积提高约15%。(2)氧化石墨烯还原过程中,探究了不同反应温度、时间和还原剂种类对产品的影响。通过表征分析,超重力还原法的还原时间比常规的机械搅拌法缩短了至少2倍,还原温度可降低15%,还原剂用量可减少35%。水合肼还原制备的石墨烯比电容量可达247 F·g-1,抗坏血酸的也在220 F·g-1以上。(3)对超重力氧化还原法和常规的超声剥离机械搅拌还原法制备的产品性能对比分析,在相同的制备条件下,超重力法制备的氧化石墨烯片层面积比常规方法大十几倍以上,厚度仅为其一半左右,石墨烯的比电容量和电容保持率提高了近20%,导电率增大了30%。旋转填料床基于其可控的剥离剪切及强化过程传质作用,不仅能够提高石墨烯的制备效率和性能,更容易规模放大,实现工业化生产。
[Abstract]:Graphene, based on its two-dimensional honeycomb monatomic layer structure, has shown outstanding properties in the fields of mechanics, heat, optics and electricity, and has aroused a great deal of research on its foundation and applications, including supercapacitors.Sensors, solar cells, etc.In this paper, the influence of different factors on the structure and properties of graphene prepared by high gravity rotating packed bed was studied. A new method of controllable scale preparation of high performance graphene was established, and it was peeled with conventional ultrasonic method.Comparative analysis of mechanical agitation reduction method.The results show that the volume of the filler in the rotating packed bed has the most significant influence on the graphite oxide exfoliation process, followed by the stripping time, the concentration of graphite oxide suspension and the rotor speed.The structure of graphene oxide prepared under different conditions was studied. The optimum conditions were chosen to prepare graphene bilayer with a lamellar area of more than 6 渭 m ~ 2, with a specific surface area of 735 m ~ 2 g ~ (-1).The concentration of hypergravity peeling is 1.5mg mL-1, which is higher than that of ultrasonic peeling in the concentration range of 0.1 ~ 1.0 mg mL-1.By adding auxiliary reagent or using rotating packed bed and ultrasonic device to optimize the stripping process, the specific surface area of graphene oxide can be increased by about 15%.The effect of time and reducing agent on the product.The reduction time of hypergravity reduction method is reduced by at least 2 times than that of conventional mechanical stirring method. The reduction temperature can be reduced by 15 times and the amount of reductant can be reduced by 35%.The specific capacity of graphene prepared by hydrazine hydrate reduction can reach 247 F g -1, and that of ascorbic acid is also above 220 F g -1. The properties of the products prepared by hypergravity redox method and conventional ultrasonic stripping mechanical agitation reduction method are compared and analyzed under the same preparation conditions.The area of graphene oxide prepared by hypergravity method is more than ten times larger than that of the conventional method, and its thickness is only about half. The specific capacitance and capacitance retention rate of graphene are increased by nearly 20%, and the conductivity is increased by 30%.The rotating packed bed can not only improve the preparation efficiency and performance of graphene, but also can easily scale up and realize industrial production because of its controllable stripping, shearing and mass transfer during strengthening process.
【学位授予单位】：北京化工大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TQ127.11

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