当前位置:首页 » 新闻资讯 » 行业动态

中石化新型乙苯催化剂在台塑集团成功应用

来源: 编辑: 人气:883 时间:2012-01-19

  凯茵化工讯 从中科院获悉,苏州纳米所等在快速批量制备高质量石墨烯研究方面取得进展。

  因为在半导体工业中具有良好的集成兼容性以及低廉的成本优势,铜基表面化学气相沉积(CVD)法被认为是好有潜力实现大规模制备高质量石墨烯的方法。通过近10年的努力(2007-2017),铜基CVD法已经在大批量、高质量和快速制备三个方向分别取得了一系列的突破进展。

  然而,对于能够同时实现快速、大批量和高质量制备石墨烯,仍然是一个挑战。分析其原因主要有三点:铜衬底和石墨烯晶格失匹配,导致石墨烯的晶界密度过高,削弱了石墨烯的物理性能;为了抑制石墨烯成核,传统的CVD方法往往通过降低碳源浓度来实现,导致石墨烯的生长速率偏低,在0.03 m/s-0.36 m/s之间;随着石墨烯制备面积的不断扩大,石墨烯生长气氛因为受流阻的影响变得不均匀,导致大批量制备的石墨烯不连续或者不均匀。

  针对以上关键科学技术问题,中国科学院苏州纳米技术与纳米仿生研究所研究员刘立伟课题组和苏州格瑞丰纳米科技有限公司合作,S先对铜衬底进行晶向调控,揭示了氧化层对铜衬底晶向的调控作用和机制。研究发现铜表面氧化层有利于Cu(001)晶向的形成,而用氢气去除铜表面氧化层后,铜衬底则迅速转变为Cu(111)晶向,并利用密度泛函理论计算揭示了氧对铜衬底晶向转变影响的机制。该工作揭示了氧气和氢气在铜衬底晶向转变中的作用,同时也有利于单晶化衬底实现高质量石墨烯的可控制备。相关结果已经发表于《科学报告》。

  基于上述研究成果,该团队提出了通过构建一个基于分子热运动的静态常压CVD(SAPCVD)系统,实现了快速批量制备硅胶类高质量石墨烯。实验结果证明SAPCVD系统能够同时在20层铜衬底上批量化制备光学均匀的石墨烯,其生长速率达到1.5 m/s。通过调控石墨烯和铜衬底的晶格失匹配,石墨烯的晶界密度得到有效抑制。

  据悉,相比于传统低压流动CVD(LPCVD)或者常压流动CVD(APCVD)系统,SAPCVD系统制备石墨烯的优点主要体现在3点:S先,石墨烯生长气氛均匀且不受流阻的影响,有利于大批量制备石墨烯;其次,碳源浓度可以在1500%的大窗口下实现均匀单层石墨烯,更容易获得光学均匀的石墨烯薄膜;好后,碳源可以在CVD生长室内充分地分解,并且可以有效降低石墨烯制备过程中对真空设备的依赖,降低了石墨烯的制备成本。该工作提出通过静态常压CVD技术和Cu(111)单晶叠层衬底技术实现快速批量制备高质量石墨烯,加速了石墨烯在柔性电子器件中的应用。

Progress has been made in rapid and batch preparation of high quality graphene

Kai Yan Chemical News learned from the Chinese Academy of Sciences, Suzhou nano-rapid progress in the preparation of high-quality graphene batch progress.

Due to its good integration and low cost advantages in the semiconductor industry, copper-based surface chemical vapor deposition (CVD) is considered to be the most promising method for large-scale production of high-quality graphene. Through nearly 10 years of efforts (2007-2017), copper-based CVD has made a series of breakthroughs in three directions, namely, high-volume, high-quality and rapid preparation.

However, it is still a challenge to be able to simultaneously produce graphene in a fast, high volume and high quality. There are mainly three reasons for the analysis: the lattice mismatch between the copper substrate and the graphene leads to an excessively high grain boundary density of the graphene, which impairs the physical properties of the graphene. In order to suppress the nucleation of the graphene, Carbon source concentration, resulting in the low growth rate of graphene, between 0.03 μ m / s-0.36 μ m / s; with the graphene preparation area continues to expand, due to the flow of graphene growth atmosphere The effect becomes non-uniform, resulting in discontinuous or non-uniform graphene prepared in large quantities.

In response to the above key scientific and technological issues, the team of Liu Liwei, a researcher at the Suzhou Institute of Nanotechnology and Nanostructure Biology, Chinese Academy of Sciences, in collaboration with Suzhou Grundfos Nanotechnology Co., Ltd., first conducted a crystal orientation control of the copper substrate, revealing Regulatory Effect and Mechanism of Oxide Layer on the Orientation of Copper Substrate. The results show that the copper surface oxide layer favors the formation of Cu (001) crystal orientation. However, the removal of copper oxide layer on the surface of the copper substrate rapidly changes to Cu (111) crystal orientation and the density functional theory Effect of Oxygen on the Crystalline Transformation of Copper Substrate. This work revealed the role of oxygen and hydrogen in the crystal orientation transition of the copper substrate, and at the same time, it is also conducive to the controlled preparation of high-quality graphene on a single-crystal substrate. Relevant results have been published in the "Science Report."

Based on the above research results, the team proposed a rapid and batch preparation of high quality graphene by constructing a static atmospheric pressure CVD (SAPCVD) system based on molecular thermal motion. The experimental results show that the SAPCVD system can batch-prepare optically homogeneous graphene simultaneously on 20 layers of copper substrate with a growth rate of 1.5 μ m / s. By controlling the lattice mismatch between graphene and copper substrate, the grain boundary density of graphene can be effectively suppressed. It is reported that, compared with the traditional low-pressure flow CVD (LPCVD) or atmospheric pressure flow CVD (APCVD) system, the advantages of SAPCVD graphene preparation mainly in the three points: First, the graphene growth atmosphere is uniform and not The flow resistance can be used to prepare graphene in large quantities. Secondly, the carbon source concentration can achieve uniform monolayer graphene under a large window of 1500%, and the optical uniform graphene film can be obtained more easily. Finally, CVD growth chamber to fully decompose, and can effectively reduce the dependence on the vacuum equipment in the graphene preparation process, reducing the production cost of graphene. This work proposed to rapidly and massively prepare high quality graphene by static atmospheric pressure CVD and Cu (111) single crystal laminated substrate technology and accelerate the application of graphene in flexible electronic devices.

TAG:
凯茵化工公众号

【版权声明】秉承互联网开放、包容的精神,凯茵化工欢迎各方(自)媒体、机构转载、引用我们原创内容,但要注明来源凯茵化工;同时,我们倡导尊重与保护知识产权,如发现本站文章存在版权问题,请将版权疑问、授权证明、版权证明、联系方式等,发邮件至 app@shkingchem.com,我们将第一时间核实、处理,感谢您的配合。

【版权声明】秉承互联网开放、包容的精神,凯茵化工欢迎各方(自)媒体、机构转载、引用我们原创内容,但要注明来源凯茵化工;同时,我们倡导尊重与保护知识产权,如发现本站文章存在版权问题,请将版权疑问、授权证明、版权证明、联系方式等,发邮件至 app@shkingchem.com,我们将第一时间核实、处理,感谢您的配合。

点击/扫码填问卷