Structure-Controlled Growth of Single-Walled Carbon Nanotubes
Single-walled carbon nanotubes (SWNTs) presents unique structure-dependent properties. Therefore, the structure(or chirality)-controlled preparation of SWNTs is a crucial issue for their advanced applications and has been a great challenge since 1990s. We developed a strategy to synthesize SWNTs with a specific chirality by using intermetallic compound W6Co7 nanocrystals as catalysts. Attributed to the collaboration of structural template effect of the catalyst and the optimized kinetic growth conditions, we were able to relealize the chirality-specified growth of SWNTs of different chiralities. The mechanism of the slective growth was further verified by in situ studies. Tracking Co7W6 nanocrystals by environmental aberration-corrected transmission electron microscope in combination with in situ synchrotron X-ray absorption spectroscopy, we directly present the structural and chemical stability of the Co7W6 nanocrystals in methane, carbon monoxide, and hydrogen at the temperature of 700–1100 C. We also observed the in situ growth of SWNTs. It is obvious that the structure of Co7W6 nanocrystals maintain their atomic structure during the growth. These observations confirmed that the catalysts act as the structural templates for SWNT growth.
单壁碳纳米管(SWNT)拥有其结构所赋予的优异的性质。结构(亦称“手性”)可控的制备是SWNT高端应用的基本要求，也是上世纪九十年代以来一直困扰业内的难题。我们发展了一种以具有独特结构的金属间化合物Co7W6 为催化剂合成单一手性SWNTs的方法。依赖于催化剂的结构模板作用和优化的生长动力学条件的协同效应，我们实现了多种单一手性单壁碳纳米管的合成。我们还用原位方法进一步研究了选择性生长的机制。利用环境球差电镜的原位生长观测，并结合原位的同步辐射x-射线吸收光谱研究，我们发现在700-1100C下，Co7W6 在甲烷、一氧化碳和氢气等气氛中保持结构稳定，证明其可以在高温下做SWNT生长的结构模板。
Prof. Yan Li joined the faculty of Chemistry, Peking University in 1995 and has been the full professor of chemistry at Peking University since 2002. She was also appointed as visiting associate professor in Duke University from November 1999 to May 2001 and distinguished visiting professor in The University of Tokyo from August 2016 to March 2019. Her research is focused on carbon nanomaterials, especially the preparation, modification, characterization and application of carbon nanotubes.
Yan Li has received many awards and honors, such as The National Science Fund for Distinguished Young Scholars (2011), Chang Jiang Scholar by Chinese Ministry of Education (2013), Chemical Innovation Award Distinguished Scientist by Chinese Chemical Society (2018), Outstanding Researcher by China Association for Science and Technology (2015), first class prize of Natural Science Award of Chinese Ministry of Education (2017), first class prize of CAIA (2017), fellow of Royal Society of Chemistry (2014), fellow of School of Engineering at The University of Tokyo (2019), etc. Currently, she is serving as the associated editor of ACS Nano. She is also on the editorial or advisory board of several journals including Nano Research, Chemical Society Reviews, and Materials Horizons. She is also in the committees of several international academic organizations.
李彦获得了许多奖荣誉和奖励，例如国家杰出青年科学基金(2011)、教育部长江学者特聘教授(2013)、中国化学会-赢创化学创新奖杰出科学家(2018)、全国优秀科技工作者(2015)、国务院政府特殊津贴(2016)、教育部自然科学一等奖(2017)、分析测试学会一等奖(2015)、英国皇家化学会会士(2014)、北京市高等学校教学名师(2013)、北京大学十佳教师(2008)、北京大学十佳导师(2015)等。李彦现兼任ACS Nano副主编，并任多个著名学术期刊，例如Nano Research、 Chemical Society Reviews、Materials Horizons等的编委和顾问编委。她也是多个国际学术组织的委员会成员。