Quantum chemical simulations reveal acetylene-based growth mechanisms in the chemical vapor deposition synthesis of carbon nanotubes
文献类型：期刊论文
| ; | |
| 作者 | Wang, Y; 高兴发;Gao, XF; Qian, HJ; Ohta, Y; Wu, XN; Eres, G; Morokuma, K; Irle, S |
| 刊名 | CARBON
 ; CARBON
|
| 出版日期 | 2014 ; 2014 |
| 卷号 | 72页码:22-37 |
| ISSN号 | 0008-6223 |
| DOI | 10.1016/j.carbon.2014.01.020 |
| 英文摘要 | Nonequilibrium quantum chemical molecular dynamics (QM/MDs) simulation of early stages in the nucleation process of carbon nanotubes from acetylene feedstock on an Fe-38 cluster was performed based on the density-functional tight-binding (DFTB) potential. Representative chemical reactions were studied by complimentary static DFTB and density functional theory (DFT) calculations. Oligomerization and cross-linking reactions between carbon chains were found as the main reaction pathways similar to that suggested in previous experimental work. The calculations highlight the inhibiting effect of hydrogen for the condensation of carbon ring networks, and a propensity for hydrogen disproportionation, thus enriching the hydrogen content in already hydrogen-rich species and abstracting hydrogen content in already hydrogen-deficient clusters. The ethynyl radical C2H was found as a reactive, yet continually regenerated species, facilitating hydrogen transfer reactions across the hydrocarbon clusters. The nonequilibrium QM/MD simulations show the prevalence of a pentagon-first nucleation mechanism where hydrogen may take the role of one "arm" of an sp(2) carbon Y-junction. The results challenge the importance of the metal carbide formation for SWCNT cap nucleation in the VLS model and suggest possible alternative routes following hydrogen-abstraction acetylene addition (HACA)-like mechanisms commonly discussed in combustion synthesis. (C) 2014 Elsevier Ltd. All rights reserved.; Nonequilibrium quantum chemical molecular dynamics (QM/MDs) simulation of early stages in the nucleation process of carbon nanotubes from acetylene feedstock on an Fe-38 cluster was performed based on the density-functional tight-binding (DFTB) potential. Representative chemical reactions were studied by complimentary static DFTB and density functional theory (DFT) calculations. Oligomerization and cross-linking reactions between carbon chains were found as the main reaction pathways similar to that suggested in previous experimental work. The calculations highlight the inhibiting effect of hydrogen for the condensation of carbon ring networks, and a propensity for hydrogen disproportionation, thus enriching the hydrogen content in already hydrogen-rich species and abstracting hydrogen content in already hydrogen-deficient clusters. The ethynyl radical C2H was found as a reactive, yet continually regenerated species, facilitating hydrogen transfer reactions across the hydrocarbon clusters. The nonequilibrium QM/MD simulations show the prevalence of a pentagon-first nucleation mechanism where hydrogen may take the role of one "arm" of an sp(2) carbon Y-junction. The results challenge the importance of the metal carbide formation for SWCNT cap nucleation in the VLS model and suggest possible alternative routes following hydrogen-abstraction acetylene addition (HACA)-like mechanisms commonly discussed in combustion synthesis. (C) 2014 Elsevier Ltd. All rights reserved. |
| 学科主题 | Chemistry; Materials Science ; Chemistry; Materials Science |
| 收录类别 | SCI |
| 电子版国际标准刊号 | 1873-3891 |
| 语种 | 英语 |
| WOS记录号 | WOS:000334010600004 ; WOS:000334010600004 |
| 公开日期 | 2016-05-03 |
| 源URL | [http://ir.ihep.ac.cn/handle/311005/224869]  |
| 专题 | 高能物理研究所_多学科研究中心 |
| 推荐引用方式 GB/T 7714 | Wang, Y,高兴发；Gao, XF,Qian, HJ,et al. Quantum chemical simulations reveal acetylene-based growth mechanisms in the chemical vapor deposition synthesis of carbon nanotubes, Quantum chemical simulations reveal acetylene-based growth mechanisms in the chemical vapor deposition synthesis of carbon nanotubes[J]. CARBON, CARBON,2014, 2014,72, 72:22-37, 22-37. |
| APA | Wang, Y.,高兴发；Gao, XF.,Qian, HJ.,Ohta, Y.,Wu, XN.,...&Irle, S.(2014).Quantum chemical simulations reveal acetylene-based growth mechanisms in the chemical vapor deposition synthesis of carbon nanotubes.CARBON,72,22-37. |
| MLA | Wang, Y,et al."Quantum chemical simulations reveal acetylene-based growth mechanisms in the chemical vapor deposition synthesis of carbon nanotubes".CARBON 72(2014):22-37. |
入库方式： OAI收割
来源：高能物理研究所
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