金属催化非晶碳的石墨烯转变研究

发布时间：2018-04-14 21:40

  本文选题：石墨烯 + 非晶碳　； 参考：《哈尔滨工业大学》2015年硕士论文

【摘要】：石墨烯是碳原子经SP2杂化所形成的具有单原子厚度的二维材料。石墨烯性能优越,如超高的电子迁移率(200000cm2v-1s-1)、优异的力学性能(杨氏模量1100GPa、断裂强度13GPa)、良好的光透过性(97%)和超大的比表面积(2630m2/g),这不仅使得其发现之初就受到了科学家的青睐,更使其在能源化工、信息材料和生物工程等诸多领域都得到了大量的研究。石墨烯是21世纪最耀眼的材料之一,其发现者仅仅4年后就获得了诺贝尔奖。经过十一年的发展,石墨烯研究取得了巨大的进步,但是目前制约着石墨烯产业化应用的主要瓶颈依然是石墨烯制备工艺的优化,如何能够制备层数可控的高质量石墨烯技术一直是迫切需要解决的问题。本文以非晶碳为碳源,金属Cu和Ni为催化金属,通过构建基底-非晶碳-催化金属的“三明治”结构,在真空下经高温退火制备石墨烯,主要研究了不同的催化金属、不同的温度参数和不同的非晶碳含量对生成石墨烯的影响,最终获得了一种可控制备石墨烯的工艺路线。研究发现,温度是决定石墨烯形成的重要参数。金属Cu作为催化剂时,当温度低于900℃时并不能生成石墨烯,900℃是在Cu催化下可以形成石墨烯的理想温度,若温度继续升高,则制得的石墨烯缺陷增多,同时杂质碳的含量也增多。在温度保证不变的条件下,可以通过改变保温时间来控制生成石墨烯的层数,其效果远远好于直接减少碳含量来控制石墨烯层数的方法,最终可以获得单层的石墨烯,但是其尺寸较小、缺陷较大。本文通过共溅射的方式引入金属Ni,利用Cu-Ni合金进行催化,使得非晶碳在高温下溶解在金属Ni中,利用Cu来抑制非晶碳的量,在降温的过程中金属Cu与Ni互溶,C在表面析出制得石墨烯。随着Ni的加入,可以在低于900℃条件下获得石墨烯,但需要延长保温时间以利于非晶碳溶解在金属Ni中,800℃保温5min下制得单层的石墨烯,且石墨烯的产量明显增多、缺陷较少。并且通过延长保温时间可以制得多层石墨烯。若金属Ni的含量过多,则制得的石墨烯结构缺陷较大,层数很难控制。当金属Ni的含量为13.63at%所获得的石墨烯质量最佳。
[Abstract]:Graphene is a two-dimensional material with the thickness of a single atom formed by SP2 hybridization of carbon atoms.The excellent properties of graphene, such as the ultra-high electron mobility of 200000cm2v-1s-1s, excellent mechanical properties (Young's modulus 1100GPaA, fracture strength 13GPaA, good light transmittance) and large specific surface area of 2630mm2 / g, not only made it attractive to scientists at the beginning of its discovery,It has been studied in many fields, such as energy, chemical industry, information materials and bioengineering.Graphene is one of the most dazzling materials of the 21 st century, and its discoverer won the Nobel Prize just four years later.After eleven years of development, great progress has been made in graphene research, but at present, the main bottleneck restricting the industrial application of graphene is the optimization of graphene preparation process.How to prepare high quality graphene with controllable number of layers is an urgent problem.In this paper, using amorphous carbon as carbon source and metal Cu and Ni as catalytic metals, the "sandwich" structure of substrate-amorphous carbon-catalytic metal was constructed, and graphene was prepared by high temperature annealing in vacuum. Different catalytic metals were studied.The effect of different temperature parameters and amorphous carbon content on the formation of graphene was investigated, and a controllable process for preparing graphene was obtained.It is found that temperature is an important parameter to determine the formation of graphene.When Cu is used as catalyst, when the temperature is below 900 鈩，

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