1
|
Chen X, Duan H, Cao B. Evolution Mechanism of Solid-Phase Catalysts During Catalytic Growth of Single-Walled Carbon Nanotubes. SMALL (WEINHEIM AN DER BERGSTRASSE, GERMANY) 2024; 20:e2310543. [PMID: 38185805 DOI: 10.1002/smll.202310543] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/16/2023] [Revised: 12/25/2023] [Indexed: 01/09/2024]
Abstract
Using solid nanoparticles (NPs) as catalysts is the most effective method to achieve catalytic growth of single-walled carbon nanotubes (SWCNTs) with ultrapure chirality. Until now, SWCNTs with a suitable chirality purity have not been prepared in experiments. That is, the evolution of solid NPs during the catalytic growth of SWCNTs is in contradiction with the original concept of a changeless structure. Hence, in this work, the evolution mechanism of solid cobalt NPs during the nucleation process of SWCNTs is analyzed through molecular dynamics. Similar to the experimental observations, the results show that a drastic structural fluctuation of the NPs occurs during the nucleation of SWCNTs. This structural fluctuation is caused by the fact that the elastic strain energy and surface energy of the NPs can be tuned when a carbon gradient exists between the subsurface and interior of the NP. Furthermore, such a carbon gradient can be reduced by changing the carbon feeding rate. This work not only reveals the evolution mechanism of solid catalysts during the nucleation of SWCNTs but also provides prospects for realizing solid catalysts with a changeless structure by tuning the experimental parameters.
Collapse
Affiliation(s)
- Xuan Chen
- School of Physical Science and Technology, Xinjiang University, Urumqi, 830046, P. R. China
| | - Haiming Duan
- School of Physical Science and Technology, Xinjiang University, Urumqi, 830046, P. R. China
- Xinjiang Key Laboratory of Solid State Physics and Devices, Xinjiang University, Urumqi, 830046, P. R. China
| | - Biaobing Cao
- School of Physical Science and Technology, Xinjiang University, Urumqi, 830046, P. R. China
| |
Collapse
|
2
|
Hedman D, McLean B, Bichara C, Maruyama S, Larsson JA, Ding F. Dynamics of growing carbon nanotube interfaces probed by machine learning-enabled molecular simulations. Nat Commun 2024; 15:4076. [PMID: 38744824 PMCID: PMC11094095 DOI: 10.1038/s41467-024-47999-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2023] [Accepted: 04/15/2024] [Indexed: 05/16/2024] Open
Abstract
Carbon nanotubes (CNTs), hollow cylinders of carbon, hold great promise for advanced technologies, provided their structure remains uniform throughout their length. Their growth takes place at high temperatures across a tube-catalyst interface. Structural defects formed during growth alter CNT properties. These defects are believed to form and heal at the tube-catalyst interface but an understanding of these mechanisms at the atomic-level is lacking. Here we present DeepCNT-22, a machine learning force field (MLFF) to drive molecular dynamics simulations through which we unveil the mechanisms of CNT formation, from nucleation to growth including defect formation and healing. We find the tube-catalyst interface to be highly dynamic, with large fluctuations in the chiral structure of the CNT-edge. This does not support continuous spiral growth as a general mechanism, instead, at these growth conditions, the growing tube edge exhibits significant configurational entropy. We demonstrate that defects form stochastically at the tube-catalyst interface, but under low growth rates and high temperatures, these heal before becoming incorporated in the tube wall, allowing CNTs to grow defect-free to seemingly unlimited lengths. These insights, not readily available through experiments, demonstrate the remarkable power of MLFF-driven simulations and fill long-standing gaps in our understanding of CNT growth mechanisms.
Collapse
Affiliation(s)
- Daniel Hedman
- Center for Multidimensional Carbon Materials (CMCM), Institute for Basic Science (IBS), Ulsan, 44919, Republic of Korea.
| | - Ben McLean
- Center for Multidimensional Carbon Materials (CMCM), Institute for Basic Science (IBS), Ulsan, 44919, Republic of Korea
- School of Engineering, RMIT University, Victoria, 3001, Australia
| | | | - Shigeo Maruyama
- Department of Mechanical Engineering, The University of Tokyo, Tokyo, 113-8656, Japan
| | - J Andreas Larsson
- Applied Physics, Division of Materials Science, Department of Engineering Sciences and Mathematics, Luleå University of Technology, Luleå, 971 87, Sweden.
| | - Feng Ding
- Center for Multidimensional Carbon Materials (CMCM), Institute for Basic Science (IBS), Ulsan, 44919, Republic of Korea.
- Department of Materials Science and Engineering, Ulsan National Institute of Science and Technology (UNIST), Ulsan, 44919, Republic of Korea.
- Faculty of Materials Science and Engineering, Institute of Technology for Carbon Neutrality, Shenzhen Institute of Advanced Technology Chinese Academy of Sciences, Shenzhen, 518055, China.
| |
Collapse
|
3
|
Chrystie RSM. A Review on 1-D Nanomaterials: Scaling-Up with Gas-Phase Synthesis. CHEM REC 2023; 23:e202300087. [PMID: 37309743 DOI: 10.1002/tcr.202300087] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2023] [Revised: 05/04/2023] [Indexed: 06/14/2023]
Abstract
Nanowire-like materials exhibit distinctive properties comprising optical polarisation, waveguiding, and hydrophobic channelling, amongst many other useful phenomena. Such 1-D derived anisotropy can be further enhanced by arranging many similar nanowires into a coherent matrix, known as an array superstructure. Manufacture of nanowire arrays can be scaled-up considerably through judicious use of gas-phase methods. Historically, the gas-phase approach however has been extensively used for the bulk and rapid synthesis of isotropic 0-D nanomaterials such as carbon black and silica. The primary goal of this review is to document recent developments, applications, and capabilities in gas-phase synthesis methods of nanowire arrays. Secondly, we elucidate the design and use of the gas-phase synthesis approach; and finally, remaining challenges and needs are addressed to advance this field.
Collapse
Affiliation(s)
- Robin S M Chrystie
- Department of Chemical Engineering, King Fahd University of Petroleum & Minerals, KFUPM Box 5050, Dhahran, 31261, Saudi Arabia
- IRC for Membranes & Water Security, King Fahd University of Petroleum & Minerals, KFUPM Box 5051, Dhahran, 31261, Saudi Arabia
| |
Collapse
|