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Shi H, He Y, Li Y, Luo P. 2D MOF derived cobalt and nitrogen-doped ultrathin oxygen-rich carbon nanosheets for efficient Fenton-like catalysis: Tuning effect of oxygen functional groups in close vicinity to Co-N sites. JOURNAL OF HAZARDOUS MATERIALS 2023; 443:130345. [PMID: 36444076 DOI: 10.1016/j.jhazmat.2022.130345] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/11/2022] [Revised: 10/16/2022] [Accepted: 11/06/2022] [Indexed: 06/16/2023]
Abstract
Developing highly efficient catalysts for peroxymonosulfate (PMS) activation is an important issue in advanced oxidation processes (AOPs) technology. In this work, cobalt and nitrogen-doped ultrathin oxygen-rich carbon nanosheets derived from 2D metal-organic framework (MOF) were successfully fabricated. The as-prepared catalyst can effectively degrade tetracycline (TC) with a high reaction constant (0.088 min-1). Quenching test, electron paramagnetic resonance (EPR) technology, and the electrochemical test indicate that the radical pathway plays a minor role in the degradation process, the 1O2 based nonradical pathway dominates the reaction. Experimental and density functional theory (DFT) studies revealed that the Co-N sites on the carbon structure serve as the dominant active sites, and the oxygen functional groups in close vicinity to Co-N sites can dramatically influence local electronic structure and its interaction with PMS molecule, a high correlation between the reaction constant and hydroxy groups content could be due to the Co-N sites close to hydroxyl groups has a moderate PMS adsorption energy. This work provides new insight into the design of highly efficient Fenton-like catalysts.
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Affiliation(s)
- Heng Shi
- College of Chemistry and Chemical Engineering. Southwest Petroleum University, Sichuan 610500, PR China; Oil & Gas Field Applied Chemistry Key Laboratory of Sichuan Province, Southwest Petroleum University, Sichuan 610500, PR China
| | - Yi He
- College of Chemistry and Chemical Engineering. Southwest Petroleum University, Sichuan 610500, PR China; Oil & Gas Field Applied Chemistry Key Laboratory of Sichuan Province, Southwest Petroleum University, Sichuan 610500, PR China; State Key Laboratory of Oil & Gas Reservoir Geology and Exploitation, Southwest Petroleum University, PR China.
| | - Yubin Li
- School of New Energy and Materials, Southwest Petroleum University, Sichuan 610500, PR China
| | - Pingya Luo
- College of Chemistry and Chemical Engineering. Southwest Petroleum University, Sichuan 610500, PR China; Oil & Gas Field Applied Chemistry Key Laboratory of Sichuan Province, Southwest Petroleum University, Sichuan 610500, PR China
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2
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Model Study of CNT-Based PEMFCs’ Electrocatalytic Layers. Catalysts 2022. [DOI: 10.3390/catal12101227] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
One of the most important problems in the development of proton-exchange membrane fuel cells (PEMFCs) is the selection of an efficient support material to serve as the electrocatalyst, which can ensure PEMFCs’ durability at low active metal loading, with minimal changes in the electrochemical surface and conductivity during long-term operations. Carbon nanostructures are now widely used in PEMFCs as such support materials, including carbon nanotubes (CNTs). In order to estimate the effect of the geometric parameters of a CNT-based support on the resulting size distribution of platinum nanoparticles for given synthesis conditions, in this work, we propose a semi-empirical model that assumes a random uniform distribution of platinum particles over the CNT surface. Based on the obtained distribution, the electrochemically active surface area (EASA) of the electrocatalyst is calculated and further used to evaluate the performance of the catalytic layer (CL) in the PEMFC. The applicability of the proposed model for calculating the parameters of CNT-based CLs and the output electrochemical characteristics of PEMFCs is shown.
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Aghaei A, Shaterian M, Hosseini-Monfared H, Farokhi A. Single-walled carbon nanotubes: synthesis and quantitative purification evaluation by acid/base treatment for high carbon impurity elimination. CHEMICAL PAPERS 2022. [DOI: 10.1007/s11696-022-02478-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
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4
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Sakurai S, Yamada M, He J, Hata K, Futaba DN. A Hydrogen-Free Approach for Activating an Fe Catalyst Using Trace Amounts of Noble Metals and Confinement into Nanoparticles. J Phys Chem Lett 2022; 13:1879-1885. [PMID: 35175057 DOI: 10.1021/acs.jpclett.2c00144] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/14/2023]
Abstract
Metallic iron (Fe) represents an exceptionally active catalyst, as shown in its use in the Haber-Bosch process to dissociate nitrogen molecules; however, the ease of corrosion by oxidation limits its usage. Hence, in most applications using metallic Fe catalysts, hydrogen is a necessary reactant. We report a novel hydrogen-free approach to fabricating reduced, highly active, and corrosion-resistive Fe-based catalysts using trace levels of noble metals (NMs) such as Ir, Rh, and Pt confined in the nanoparticle (NP). X-ray photoelectron spectroscopy (XPS) revealed that as little as ∼0.3 atom % was sufficient to induce the reduction of Fe. Extensive XPS analysis showed that the reduced NM atoms segregated to the NP surface and reduced the surrounding Fe atoms. We demonstrated the catalytic activity of the nanoparticles by the efficient synthesis of submillimeter tall, vertically aligned, and mainly double-walled carbon nanotube arrays using a completely hydrogen-free chemical vapor deposition process.
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Affiliation(s)
- Shunsuke Sakurai
- CNT-Application Research Center, National Institute of Advanced Industrial Science and Technology (AIST), Tsukuba Central 5, 1-1-1 Higashi, Tsukuba, Ibaraki 305-8565, Japan
| | - Maho Yamada
- CNT-Application Research Center, National Institute of Advanced Industrial Science and Technology (AIST), Tsukuba Central 5, 1-1-1 Higashi, Tsukuba, Ibaraki 305-8565, Japan
| | - Jinping He
- CNT-Application Research Center, National Institute of Advanced Industrial Science and Technology (AIST), Tsukuba Central 5, 1-1-1 Higashi, Tsukuba, Ibaraki 305-8565, Japan
| | - Kenji Hata
- CNT-Application Research Center, National Institute of Advanced Industrial Science and Technology (AIST), Tsukuba Central 5, 1-1-1 Higashi, Tsukuba, Ibaraki 305-8565, Japan
| | - Don N Futaba
- CNT-Application Research Center, National Institute of Advanced Industrial Science and Technology (AIST), Tsukuba Central 5, 1-1-1 Higashi, Tsukuba, Ibaraki 305-8565, Japan
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5
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Koji H, Kusumoto Y, Hatta A, Furuta H. Formation of Thermally Stable, High-Areal-Density, and Small-Diameter Catalyst Nanoparticles via Intermittent Sputtering Deposition for the High-Density Growth of Carbon Nanotubes. NANOMATERIALS 2022; 12:nano12030365. [PMID: 35159710 PMCID: PMC8838723 DOI: 10.3390/nano12030365] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/15/2021] [Revised: 01/20/2022] [Accepted: 01/21/2022] [Indexed: 02/01/2023]
Abstract
We report the formation of thermally stable catalyst nanoparticles via intermittent sputtering deposition to prevent the agglomeration of the nanoparticles during thermal chemical vapor deposition (CVD) and for the high-density growth of carbon nanotubes (CNTs). The preparation of high-areal-density and small-diameter catalyst nanoparticles on substrates for the high-density growth of CNTs is still a challenging issue because surface diffusion and Ostwald ripening of the nanoparticles induce agglomeration, which results in the low-density growth of large-diameter CNTs during high-temperature thermal CVD. Enhancing the adhesion of nanoparticles or suppressing their diffusion on the substrate to retain a small particle diameter is desirable for the preparation of thermally stable, high-areal-density, and small-diameter catalyst nanoparticles. The intermittent sputtering method was employed to deposit Ni and Fe metal nanoparticles on a substrate for the synthesis of high-areal-density CNTs for Fe nanoparticle catalyst films. The metal particles deposited via intermittent sputtering with an interval time of over 30 s maintained their areal densities and diameters during the thermal CVD process in a vacuum for CNT synthesis. An interval of over 30 s was expected to oxidize the metal particles, which resulted in thermal stability during the CVD process. The intermittent sputtering method is thus a candidate process for the preparation of thermally stable catalyst films for the growth of a high density of long CNTs, which can be combined with the present CNT production process.
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Affiliation(s)
- Hirofumi Koji
- School of Systems Engineering, Kochi University of Technology, 185 Miyanokuchi, Kami, Kochi 782-8502, Japan; (Y.K.); (A.H.)
- National Institute of Technology, Kitakyushu College, 5-20-1 Shii, Kokuraminami-ku, Kitakyushu, Fukuoka 802-0985, Japan
- Correspondence: (H.K.); (H.F.)
| | - Yuji Kusumoto
- School of Systems Engineering, Kochi University of Technology, 185 Miyanokuchi, Kami, Kochi 782-8502, Japan; (Y.K.); (A.H.)
| | - Akimitsu Hatta
- School of Systems Engineering, Kochi University of Technology, 185 Miyanokuchi, Kami, Kochi 782-8502, Japan; (Y.K.); (A.H.)
- Center for Nanotechnology, Research Institute, Kochi University of Technology, 185 Miyanokuchi, Kami, Kochi 782-8502, Japan
| | - Hiroshi Furuta
- School of Systems Engineering, Kochi University of Technology, 185 Miyanokuchi, Kami, Kochi 782-8502, Japan; (Y.K.); (A.H.)
- Center for Nanotechnology, Research Institute, Kochi University of Technology, 185 Miyanokuchi, Kami, Kochi 782-8502, Japan
- Correspondence: (H.K.); (H.F.)
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Radman H, Baniadam M, Maghrebi M, Hamed Mosavian MT, Eshraghi MJ. Quality and Quantity of Carbon Nanotube Arrays Grown in Different Pressures and Temperatures Across Absorption-, Surface-, and Diffusion-Controlled Regimes. Ind Eng Chem Res 2020. [DOI: 10.1021/acs.iecr.0c01242] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Hassan Radman
- Department of Chemical Engineering, Ferdowsi University of Mashhad, Mashhad, Khorasan Razavi, IR 9177948944, Iran
| | - Majid Baniadam
- Department of Chemical Engineering, Ferdowsi University of Mashhad, Mashhad, Khorasan Razavi, IR 9177948944, Iran
| | - Morteza Maghrebi
- Department of Chemical Engineering, Ferdowsi University of Mashhad, Khorasan Razavi, IR 917751111, Iran
| | | | - Mohamad Javad Eshraghi
- Department of Semiconductors, Material & Energy Research Center, Meshkin dasht, Alborz, IR 477714155, Iran
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Sugime H, Sato T, Nakagawa R, Cepek C, Noda S. Gd-Enhanced Growth of Multi-Millimeter-Tall Forests of Single-Wall Carbon Nanotubes. ACS NANO 2019; 13:13208-13216. [PMID: 31674760 DOI: 10.1021/acsnano.9b06181] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
Multi-millimeter-tall vertically aligned single-wall carbon nanotube (VA-SWCNT) forests were grown using Fe/Gd/Al2Ox catalyst with high initial growth rate of ∼2 μm s-1 and long catalyst lifetime of ∼70 min at 800 °C. The addition of Gd with a nominal thickness of 0.3 nm drastically prolonged the catalyst lifetime. The analysis of the VA-SWCNT forests by a transmission electron microscope showed that the average diameter of the SWCNTs grown with Gd is constant from the top to the bottom of the forests, while it monotonically increased without Gd. This indicated that Gd suppresses the structure change of the Fe nanoparticles in the lateral direction during the CNT growth. By X-ray photoelectron spectroscopy, it was found that the longer catalyst lifetime with Gd stems from the suppression of the interaction between Fe and C resulting in the smaller structure change of the Fe nanoparticles.
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Affiliation(s)
- Hisashi Sugime
- Department of Applied Chemistry, School of Advanced Science and Engineering , Waseda University , 3-4-1 Okubo , Shinjuku-ku , Tokyo 169-8555 , Japan
| | - Toshihiro Sato
- Department of Applied Chemistry, School of Advanced Science and Engineering , Waseda University , 3-4-1 Okubo , Shinjuku-ku , Tokyo 169-8555 , Japan
| | - Rei Nakagawa
- Department of Applied Chemistry, School of Advanced Science and Engineering , Waseda University , 3-4-1 Okubo , Shinjuku-ku , Tokyo 169-8555 , Japan
| | - Cinzia Cepek
- Consiglio Nazionale delle Ricerche - Istituto Officina dei Materiali (IOM) , Area Science Park, S.S.14, Km. 163.5 , I-34149 Trieste , Italy
| | - Suguru Noda
- Department of Applied Chemistry, School of Advanced Science and Engineering , Waseda University , 3-4-1 Okubo , Shinjuku-ku , Tokyo 169-8555 , Japan
- Waseda Research Institute for Science and Engineering , Waseda University , 3-4-1 Okubo , Shinjuku-ku , Tokyo 169-8555 , Japan
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8
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Cui K, Wardle BL. Breakdown of Native Oxide Enables Multifunctional, Free-Form Carbon Nanotube-Metal Hierarchical Architectures. ACS APPLIED MATERIALS & INTERFACES 2019; 11:35212-35220. [PMID: 31514497 DOI: 10.1021/acsami.9b08290] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
Passive oxide layers on metal substrates impose remarkable interfacial resistance for electron and phonon transport. Here, a scalable surface activation process is presented for the breakdown of the passive oxide layer and the formation of nanowire/nanopyramid structured surfaces on metal substrates, which enables high-efficiency catalysis of high-crystallinity carbon nanotubes (CNTs) and the direct integration of the CNT-metal hierarchical architectures with flexible free-form configurations. The CNT-metal hierarchical architecture facilitates a dielectric free-energy-carrier transport pathway and blocks the reformation of passive oxide layer, and thus demonstrates a 5-fold decrease in interfacial electrical resistance with 66% increase in specific surface area compared with those without surface activation. Moreover, the CNT-metal hierarchical architectures demonstrate omnidirectional blackbody photoabsorption with the reflectance of 1 × 10-5 over the range from ultraviolet to terahertz region, which is 1 order of magnitude lower than that of any previously reported broadband absorber material. The synergistically incorporated CNT-metal hierarchical architectures offer record-high broadband optical absorption with excellent electrical and structural properties as well as industrial-scale producibility.
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Affiliation(s)
- Kehang Cui
- Department of Aeronautics and Astronautics , Massachusetts Institute of Technology , Cambridge , Massachusetts 02134 , United States
| | - Brian L Wardle
- Department of Aeronautics and Astronautics , Massachusetts Institute of Technology , Cambridge , Massachusetts 02134 , United States
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9
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Campo T, Pinilla S, Gálvez S, Sanz JM, Márquez F, Morant C. Synthesis Procedure of Highly Densely Packed Carbon Nanotube Forests on TiN. NANOMATERIALS 2019; 9:nano9040571. [PMID: 30965642 PMCID: PMC6523890 DOI: 10.3390/nano9040571] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/03/2019] [Revised: 03/30/2019] [Accepted: 04/02/2019] [Indexed: 11/24/2022]
Abstract
The goal of this research was to obtain high-density single-walled carbon nanotube forests (SWNTs) on conductive substrates for different applications, including field emission. For this, dip-coating was chosen as the catalyst deposition method, to subsequently grow SWNTs by Alcohol Catalytic Chemical Vapor Deposition (AC-CVD). Si (100) was chosen as the substrate, which was then coated with a TiN thin film. By sputtering with Ar, it was possible to generate alternating TiN and Si lanes, with a different wettability and, therefore, a different affinity for the catalysts. As a result, the Mo-Co catalyst was mainly deposited on TiN and not on sputtered-Si, which allowed the selective growth of SWNT forests on the TiN conductive surfaces. These as-synthesized SWNTs were used for field emission measurements in a high vacuum chamber.
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Affiliation(s)
- Teresa Campo
- Laboratory of Coatings and Nanostructures, Department of Applied Physics, Universidad Autónoma de Madrid (UAM), Cantoblanco, 28049 Madrid, Spain.
| | - Sergio Pinilla
- Laboratory of Coatings and Nanostructures, Department of Applied Physics, Universidad Autónoma de Madrid (UAM), Cantoblanco, 28049 Madrid, Spain.
- Instituto Nicolás Cabrera, Universidad Autónoma de Madrid, 28049 Madrid, Spain.
| | - Santos Gálvez
- Laboratory of Coatings and Nanostructures, Department of Applied Physics, Universidad Autónoma de Madrid (UAM), Cantoblanco, 28049 Madrid, Spain.
| | - José María Sanz
- Laboratory of Coatings and Nanostructures, Department of Applied Physics, Universidad Autónoma de Madrid (UAM), Cantoblanco, 28049 Madrid, Spain.
- Instituto Nicolás Cabrera, Universidad Autónoma de Madrid, 28049 Madrid, Spain.
| | - Francisco Márquez
- Nanomaterials Research Group, Department of Chemistry, Universidad Ana G. Méndez-Gurabo Campus, 189 St. Rd. km 3.3, Gurabo, PR 00778, USA.
| | - Carmen Morant
- Laboratory of Coatings and Nanostructures, Department of Applied Physics, Universidad Autónoma de Madrid (UAM), Cantoblanco, 28049 Madrid, Spain.
- Instituto Nicolás Cabrera, Universidad Autónoma de Madrid, 28049 Madrid, Spain.
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Rao R, Pint CL, Islam AE, Weatherup RS, Hofmann S, Meshot ER, Wu F, Zhou C, Dee N, Amama PB, Carpena-Nuñez J, Shi W, Plata DL, Penev ES, Yakobson BI, Balbuena PB, Bichara C, Futaba DN, Noda S, Shin H, Kim KS, Simard B, Mirri F, Pasquali M, Fornasiero F, Kauppinen EI, Arnold M, Cola BA, Nikolaev P, Arepalli S, Cheng HM, Zakharov DN, Stach EA, Zhang J, Wei F, Terrones M, Geohegan DB, Maruyama B, Maruyama S, Li Y, Adams WW, Hart AJ. Carbon Nanotubes and Related Nanomaterials: Critical Advances and Challenges for Synthesis toward Mainstream Commercial Applications. ACS NANO 2018; 12:11756-11784. [PMID: 30516055 DOI: 10.1021/acsnano.8b06511] [Citation(s) in RCA: 174] [Impact Index Per Article: 29.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/12/2023]
Abstract
Advances in the synthesis and scalable manufacturing of single-walled carbon nanotubes (SWCNTs) remain critical to realizing many important commercial applications. Here we review recent breakthroughs in the synthesis of SWCNTs and highlight key ongoing research areas and challenges. A few key applications that capitalize on the properties of SWCNTs are also reviewed with respect to the recent synthesis breakthroughs and ways in which synthesis science can enable advances in these applications. While the primary focus of this review is on the science framework of SWCNT growth, we draw connections to mechanisms underlying the synthesis of other 1D and 2D materials such as boron nitride nanotubes and graphene.
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Affiliation(s)
- Rahul Rao
- Materials and Manufacturing Directorate, Air Force Research Laboratory , Wright Patterson Air Force Base , Dayton , Ohio 45433 , United States
- UES Inc. , Dayton , Ohio 45433 , United States
| | - Cary L Pint
- Department of Mechanical Engineering , Vanderbilt University , Nashville , Tennessee 37235 United States
| | - Ahmad E Islam
- Materials and Manufacturing Directorate, Air Force Research Laboratory , Wright Patterson Air Force Base , Dayton , Ohio 45433 , United States
- UES Inc. , Dayton , Ohio 45433 , United States
| | - Robert S Weatherup
- School of Chemistry , University of Manchester , Oxford Road , Manchester M13 9PL , U.K
- University of Manchester at Harwell, Diamond Light Source, Didcot , Oxfordshire OX11 0DE , U.K
| | - Stephan Hofmann
- Department of Engineering , University of Cambridge , Cambridge CB3 0FA , U.K
| | - Eric R Meshot
- Physical and Life Sciences Directorate , Lawrence Livermore National Laboratory , Livermore , California 94550 United States
| | - Fanqi Wu
- Ming-Hsieh Department of Electrical Engineering , University of Southern California , Los Angeles , California 90089 , United States
| | - Chongwu Zhou
- Ming-Hsieh Department of Electrical Engineering , University of Southern California , Los Angeles , California 90089 , United States
| | - Nicholas Dee
- Department of Mechanical Engineering , Massachusetts Institute of Technology , Cambridge , Massachusetts 02139 , United States
| | - Placidus B Amama
- Tim Taylor Department of Chemical Engineering , Kansas State University , Manhattan , Kansas 66506 , United States
| | - Jennifer Carpena-Nuñez
- Materials and Manufacturing Directorate, Air Force Research Laboratory , Wright Patterson Air Force Base , Dayton , Ohio 45433 , United States
- UES Inc. , Dayton , Ohio 45433 , United States
| | - Wenbo Shi
- Department of Chemical and Environmental Engineering , Yale University , New Haven , Connecticut 06520 , United States
| | - Desiree L Plata
- Department of Civil and Environmental Engineering , Massachusetts Institute of Technology , Cambridge , Massachusetts 02139 , United States
| | - Evgeni S Penev
- Department of Materials Science and NanoEngineering , Rice University , Houston , Texas 77005 , United States
| | - Boris I Yakobson
- Department of Materials Science and NanoEngineering , Rice University , Houston , Texas 77005 , United States
| | - Perla B Balbuena
- Department of Chemical Engineering, Department of Materials Science and Engineering, Department of Chemistry , Texas A&M University , College Station , Texas 77843 , United States
| | - Christophe Bichara
- Aix-Marseille University and CNRS , CINaM UMR 7325 , 13288 Marseille , France
| | - Don N Futaba
- Nanotube Research Center , National Institute of Advanced Industrial Science and Technology (AIST) , Tsukuba 305-8565 , Japan
| | - Suguru Noda
- Department of Applied Chemistry and Waseda Research Institute for Science and Engineering , Waseda University , 3-4-1 Okubo , Shinjuku-ku, Tokyo 169-8555 , Japan
| | - Homin Shin
- Security and Disruptive Technologies Research Centre, Emerging Technologies Division , National Research Council Canada , Ottawa , Ontario K1A 0R6 , Canada
| | - Keun Su Kim
- Security and Disruptive Technologies Research Centre, Emerging Technologies Division , National Research Council Canada , Ottawa , Ontario K1A 0R6 , Canada
| | - Benoit Simard
- Security and Disruptive Technologies Research Centre, Emerging Technologies Division , National Research Council Canada , Ottawa , Ontario K1A 0R6 , Canada
| | - Francesca Mirri
- Department of Materials Science and NanoEngineering , Rice University , Houston , Texas 77005 , United States
| | - Matteo Pasquali
- Department of Materials Science and NanoEngineering , Rice University , Houston , Texas 77005 , United States
| | - Francesco Fornasiero
- Physical and Life Sciences Directorate , Lawrence Livermore National Laboratory , Livermore , California 94550 United States
| | - Esko I Kauppinen
- Department of Applied Physics , Aalto University School of Science , P.O. Box 15100 , FI-00076 Espoo , Finland
| | - Michael Arnold
- Department of Materials Science and Engineering University of Wisconsin-Madison , Madison , Wisconsin 53706 , United States
| | - Baratunde A Cola
- George W. Woodruff School of Mechanical Engineering and School of Materials Science and Engineering , Georgia Institute of Technology , Atlanta , Georgia 30332 , United States
| | - Pavel Nikolaev
- Materials and Manufacturing Directorate, Air Force Research Laboratory , Wright Patterson Air Force Base , Dayton , Ohio 45433 , United States
- UES Inc. , Dayton , Ohio 45433 , United States
| | - Sivaram Arepalli
- Department of Materials Science and NanoEngineering , Rice University , Houston , Texas 77005 , United States
| | - Hui-Ming Cheng
- Tsinghua-Berkeley Shenzhen Institute , Tsinghua University , Shenzhen 518055 , China
- Shenyang National Laboratory for Materials Science , Institute of Metal Research, Chinese Academy of Sciences , Shenyang 110016 , China
| | - Dmitri N Zakharov
- Center for Functional Nanomaterials , Brookhaven National Laboratory , Upton , New York 11973 , United States
| | - Eric A Stach
- Department of Materials Science and Engineering , University of Pennsylvania , Philadelphia , Pennsylvania 19104 , United States
| | - Jin Zhang
- College of Chemistry and Molecular Engineering , Peking University , Beijing 100871 , China
| | - Fei Wei
- Beijing Key Laboratory of Green Chemical Reaction Engineering and Technology, Department of Chemical Engineering , Tsinghua University , Beijing 100084 , China
| | - Mauricio Terrones
- Department of Physics and Center for Two-Dimensional and Layered Materials , The Pennsylvania State University , University Park , Pennsylvania 16802 , United States
| | - David B Geohegan
- Center for Nanophase Materials Sciences , Oak Ridge National Laboratory , Oak Ridge , Tennessee 37831 , United States
| | - Benji Maruyama
- Materials and Manufacturing Directorate, Air Force Research Laboratory , Wright Patterson Air Force Base , Dayton , Ohio 45433 , United States
| | - Shigeo Maruyama
- Department of Mechanical Engineering , The University of Tokyo , 7-3-1 Hongo , Bunkyo-ku , Tokyo 113-8656 , Japan
| | - Yan Li
- College of Chemistry and Molecular Engineering , Peking University , Beijing 100871 , China
| | - W Wade Adams
- Department of Materials Science and NanoEngineering , Rice University , Houston , Texas 77005 , United States
| | - A John Hart
- Department of Mechanical Engineering , Massachusetts Institute of Technology , Cambridge , Massachusetts 02139 , United States
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11
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Szabó A, Andricević P, Pápa Z, Gyulavári T, Németh K, Horvath E, Forró L, Hernadi K. Growth of CNT Forests on Titanium Based Layers, Detailed Study of Catalysts. Front Chem 2018; 6:593. [PMID: 30560119 PMCID: PMC6287110 DOI: 10.3389/fchem.2018.00593] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2018] [Accepted: 11/13/2018] [Indexed: 11/13/2022] Open
Abstract
For better electrical contacts of potential devices, growth of vertically aligned carbon nanotubes (CNT forests) directly onto conductive substrates is an emerging challenge. Here, we report a systematic study on the CCVD synthesis of carbon nanotube forests on titanium based substrates. As a crucial issue, the effect of the presence of an insulating layer (alumina) on the growing forest was investigated. Other important parameters, such as the influence of water vapor or the Fe-Co catalyst ratio, were also studied during the synthesis. As-prepared CNT forests were characterized by various techniques: scanning and transmission electron microscopies, Raman spectroscopy, spectroscopic ellipsometry. CNT forests grown directly onto the conductive substrate were also tested as electrodes in hybrid halide perovskite photodetectors and found to be effective in detecting light of intensity as low as 3 nW.
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Affiliation(s)
- Anna Szabó
- Department of Applied and Environmental Chemistry, University of Szeged, Szeged, Hungary
| | - Pavao Andricević
- Laboratory of Physics of Complex Matter (LPMC), Ecole Polytechnique Federale de Lausanne, Lausanne, Switzerland
| | - Zsuzsanna Pápa
- Department of Optics and Quantum Electronics, University of Szeged, Szeged, Hungary
| | - Tamás Gyulavári
- Department of Applied and Environmental Chemistry, University of Szeged, Szeged, Hungary
| | - Krisztián Németh
- Department of Applied and Environmental Chemistry, University of Szeged, Szeged, Hungary
| | - Endre Horvath
- Laboratory of Physics of Complex Matter (LPMC), Ecole Polytechnique Federale de Lausanne, Lausanne, Switzerland
| | - László Forró
- Laboratory of Physics of Complex Matter (LPMC), Ecole Polytechnique Federale de Lausanne, Lausanne, Switzerland
| | - Klara Hernadi
- Laboratory of Physics of Complex Matter (LPMC), Ecole Polytechnique Federale de Lausanne, Lausanne, Switzerland
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12
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Kumar R, Sahoo B. One-step pyrolytic synthesis and growth mechanism of core–shell type Fe/Fe3C-graphite nanoparticles-embedded carbon globules. ACTA ACUST UNITED AC 2018. [DOI: 10.1016/j.nanoso.2018.05.005] [Citation(s) in RCA: 30] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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13
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Modwi A, Khezami L, Taha KK, Idriss H. Flower Buds Like MgO Nanoparticles: From Characterisation to Indigo Carmine Elimination. ACTA ACUST UNITED AC 2018. [DOI: 10.1515/zna-2018-0219] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
Abstract
Abstract
Here, we demonstrate a pyrolysis route for the synthesis of flower buds like magnesium oxide nanoparticles using a magnesium carbonate precursor without additional chemicals. The effect of heating at different time intervals upon the structure and morphology of the acquired nanostructures were investigated via X-ray diffraction, scanning electron microscopy, energy dispersive X-ray analysis and Fourier transformation infrared spectroscopy. Nitrogen adsorption was employed to study its porosity. The obtained data confirmed the formation of target nanoparticles that exhibited increasing sizes as pyrolysis time was lengthened. As a consequence a high surface area up to 27 m2 g−1 was recorded for the sample heated for 1 h duration. Furthermore, Indigo Carmine dye adsorption was carried out using the largest surface area species which showed an adsorption capacity of 158 mg g−1. The adsorption was found to comply with the Langmuir isotherm and it follows the pseudo-second-order kinetics. The diffusion process showed intra-particle along with film diffusion mode.
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Affiliation(s)
- A. Modwi
- Department of Chemistry, College of Sciences , Al Imam Mohammad Ibn Saud Islamic University (IMSIU) , Riyadh 11432 , Saudi Arabia
| | - L. Khezami
- Department of Chemistry, College of Sciences , Al Imam Mohammad Ibn Saud Islamic University (IMSIU) , Riyadh 11432 , Saudi Arabia
| | - Kamal K. Taha
- Department of Chemistry, College of Sciences , Al Imam Mohammad Ibn Saud Islamic University (IMSIU) , Riyadh 11432 , Saudi Arabia
- College of Applied and Industrial Sciences, University of Bahri , Khartoum , Sudan
| | - Hajo Idriss
- Department of Physics, Committee on Radiation and Environmental Pollution Protection, College of Science , Al Imam Mohammad Ibn Saud Islamic University (IMSIU) , PO Box 90950 , Riyadh, 11623 , Saudi Arabia
- Radiation Safety Institute, Sudan Atomic Energy Commission , PO Box 3001 Khartoum , Sudan
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14
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Douglas A, Carter R, Li M, Pint CL. Toward Small-Diameter Carbon Nanotubes Synthesized from Captured Carbon Dioxide: Critical Role of Catalyst Coarsening. ACS APPLIED MATERIALS & INTERFACES 2018; 10:19010-19018. [PMID: 29715008 DOI: 10.1021/acsami.8b02834] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
Small-diameter carbon nanotubes (CNTs) often require increased sophistication and control in synthesis processes, but exhibit improved physical properties and greater economic value over their larger-diameter counterparts. Here, we study mechanisms controlling the electrochemical synthesis of CNTs from the capture and conversion of ambient CO2 in molten salts and leverage this understanding to achieve the smallest-diameter CNTs ever reported in the literature from sustainable electrochemical synthesis routes, including some few-walled CNTs. Here, Fe catalyst layers are deposited at different thicknesses onto stainless steel to produce cathodes, and atomic layer deposition of Al2O3 is performed on Ni to produce a corrosion-resistant anode. Our findings indicate a correlation between the CNT diameter and Fe metal layer thickness following electrochemical catalyst reduction at the cathode-molten salt interface. Further, catalyst coarsening during long duration synthesis experiments leads to a 2× increase in average diameters from 3 to 60 min durations, with CNTs produced after 3 min exhibiting a tight diameter distribution centered near ∼10 nm. Energy consumption analysis for the conversion of CO2 into CNTs demonstrates energy input costs much lower than the value of CNTs-a concept that strictly requires and motivates small-diameter CNTs-and is more favorable compared to other costly CO2 conversion techniques that produce lower-value materials and products.
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Affiliation(s)
- Anna Douglas
- SkyNano LLC , Oak Ridge , Tennessee 37830 , United States
| | | | | | - Cary L Pint
- Vanderbilt Institute of Nanoscale Science and Engineering , Nashville , Tennessee 37235 , United States
- SkyNano LLC , Oak Ridge , Tennessee 37830 , United States
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15
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Chen G, Dodson B, Hedges DM, Steffensen SC, Harb JN, Puleo C, Galligan C, Ashe J, Vanfleet RR, Davis RC. Fabrication of High Aspect Ratio Millimeter-Tall Free-Standing Carbon Nanotube-Based Microelectrode Arrays. ACS Biomater Sci Eng 2018; 4:1900-1907. [PMID: 33445345 DOI: 10.1021/acsbiomaterials.8b00038] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023]
Abstract
Microelectrode arrays of carbon nanotube (CNT)/carbon composite posts with high aspect ratio and millimeter-length were fabricated using carbon-nanotube-templated microfabrication with a sacrificial "hedge". The high aspect ratio, mechanical robustness, and electrical conductivity of these electrodes make them a potential candidate for next-generation neural interfacing. Electrochemical measurements were also demonstrated using an individual CNT post microelectrode with a diameter of 25 μm and a length of 1 mm to perform cyclic voltammetry on both methyl viologen and dopamine in a phosphate-buffered saline solution. In addition to detection of the characteristic peaks, the CNT post microelectrodes show a fast electrochemical response, which may be enabling for in vivo and/or in vitro measurements. The CNT post electrode fabrication process was also integrated with other microfabrication techniques, resulting in individually addressable electrodes.
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Affiliation(s)
- Guohai Chen
- Department of Physics and Astronomy, Brigham Young University, Provo, Utah 84602, United States
| | - Berg Dodson
- Department of Physics and Astronomy, Brigham Young University, Provo, Utah 84602, United States
| | - David M Hedges
- Department of Psychology and Neuroscience, Brigham Young University, Provo, Utah 84602, United States
| | - Scott C Steffensen
- Department of Psychology and Neuroscience, Brigham Young University, Provo, Utah 84602, United States
| | - John N Harb
- Department of Chemical Engineering, Brigham Young University, Provo, Utah 84602, United States
| | - Chris Puleo
- General Electric Global Research (GE-GR), 1 Research Circle, Niskayuna, New York 12309, United States
| | - Craig Galligan
- General Electric Global Research (GE-GR), 1 Research Circle, Niskayuna, New York 12309, United States
| | - Jeffrey Ashe
- General Electric Global Research (GE-GR), 1 Research Circle, Niskayuna, New York 12309, United States
| | - Richard R Vanfleet
- Department of Physics and Astronomy, Brigham Young University, Provo, Utah 84602, United States
| | - Robert C Davis
- Department of Physics and Astronomy, Brigham Young University, Provo, Utah 84602, United States
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16
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Tu F, Drost M, Szenti I, Kiss J, Kónya Z, Marbach H. Localized growth of carbon nanotubes via lithographic fabrication of metallic deposits. BEILSTEIN JOURNAL OF NANOTECHNOLOGY 2017; 8:2592-2605. [PMID: 29259874 PMCID: PMC5727812 DOI: 10.3762/bjnano.8.260] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/09/2017] [Accepted: 11/08/2017] [Indexed: 01/18/2023]
Abstract
We report on the fabrication of carbon nanotubes (CNTs) at predefined positions and controlled morphology, for example, as individual nanotubes or as CNT forests. Electron beam induced deposition (EBID) with subsequent autocatalytic growth (AG) was applied to lithographically produce catalytically active seeds for the localized growth of CNTs via chemical vapor deposition (CVD). With the precursor Fe(CO)5 we were able to fabricate clean iron deposits via EBID and AG. After the proof-of-principle that these Fe deposits indeed act as seeds for the growth of CNTs, the influence of significant EBID/AG parameters on the deposit shape and finally the yield and morphology of the grown CNTs was investigated in detail. Based on these results, the parameters could be optimized such that EBID point matrixes (6 × 6) were fabricated on a silica surface whereby at each predefined site only one CNT was produced. Furthermore, the localized fabrication of CNT forests was targeted and successfully achieved on an Al2O3 layer on a silicon sample. A peculiar lift-up of the Fe seed structures as “flakes” was observed and the mechanism was discussed. Finally, a proof-of-principle was presented showing that EBID deposits from the precursor Co(CO)3NO are also very effective catalysts for the CNT growth. Even though the metal content (Co) of the latter is reduced in comparison to the Fe deposits, effective CNT growth was observed for the Co-containing deposits at lower CVD temperatures than for the corresponding Fe deposits.
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Affiliation(s)
- Fan Tu
- Lehrstuhl für Physikalische Chemie II and Interdisciplinary Center for Molecular Materials (ICMM), Friedrich-Alexander-Universität Erlangen-Nürnberg, Egerlandstr. 3, 91058 Erlangen, Germany
| | - Martin Drost
- Lehrstuhl für Physikalische Chemie II and Interdisciplinary Center for Molecular Materials (ICMM), Friedrich-Alexander-Universität Erlangen-Nürnberg, Egerlandstr. 3, 91058 Erlangen, Germany
| | - Imre Szenti
- Department of Applied and Environmental Chemistry, University of Szeged, Szeged, Hungary
| | - Janos Kiss
- MTA-SZTE Reaction Kinetics and Surface Chemistry Research Group, University of Szeged, Rerrich ter 1, 6720 Szeged, Hungary
| | - Zoltan Kónya
- Department of Applied and Environmental Chemistry, University of Szeged, Szeged, Hungary.,MTA-SZTE Reaction Kinetics and Surface Chemistry Research Group, University of Szeged, Rerrich ter 1, 6720 Szeged, Hungary
| | - Hubertus Marbach
- Lehrstuhl für Physikalische Chemie II and Interdisciplinary Center for Molecular Materials (ICMM), Friedrich-Alexander-Universität Erlangen-Nürnberg, Egerlandstr. 3, 91058 Erlangen, Germany
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17
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Tsuji T, Hata K, Futaba DN, Sakurai S. The double-edged effects of annealing MgO underlayers on the efficient synthesis of single-wall carbon nanotube forests. NANOSCALE 2017; 9:17617-17622. [PMID: 29115340 DOI: 10.1039/c7nr06478k] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
Recently, the millimetre-scale, highly efficient synthesis of single-wall carbon nanotube (SWCNT) forests from Fe catalysts has been reported through the annealing of the magnesia (MgO) underlayer. Here, we report the double-edged effects of underlayer annealing on the efficiency and structure of the SWCNT forest synthesis through a temperature-dependent examination. Our results showed that the efficiency of the SWCNT forests sharply increased with increased underlayer annealing temperatures from 600 °C up to 900 °C due to a temperature-dependent structural modification, characterized by increased grain size and reduced defects, of the MgO underlayer. Beyond this temperature, the SWCNT fraction also decreased as a result of further structural modification of the MgO underlayer. This exemplifies the double-edged effects of annealing. Specifically, for underlayer annealing below 600 °C, the catalyst subsurface diffusion was found to limit the growth efficiency, and for excessively high underlayer annealing temperatures (>900 °C), catalyst coalescence/ripening led to the formation of double-wall carbon nanotubes. As a result, three distinct regions of synthesis were observed: (i) a "low yield" region below a threshold temperature (∼600 °C); (ii) an "increased yield" region from 600 to 900 °C, and (iii) a "saturation" region above 900 °C. The efficient SWCNT forest synthesis could only occur within a specific annealing temperature window as a result of this double-edged effects of underlayer annealing.
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Affiliation(s)
- Takashi Tsuji
- CNT-Application Research Centre, National Institute of Advanced Industrial Science and Technology (AIST), Central 5, 1-1-1, Higashi, Tsukuba, Ibaraki 305-8565, Japan.
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18
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Influence of synthesis parameters on CCVD growth of vertically aligned carbon nanotubes over aluminum substrate. Sci Rep 2017; 7:9557. [PMID: 28842644 PMCID: PMC5573477 DOI: 10.1038/s41598-017-10055-0] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2017] [Accepted: 08/01/2017] [Indexed: 11/08/2022] Open
Abstract
In the past two decades, important results have been achieved in the field of carbon nanotube (CNT) research, which revealed that carbon nanotubes have extremely good electrical and mechanical properties The range of applications widens more, if CNTs form a forest-like, vertically aligned structure (VACNT) Although, VACNT-conductive substrate structure could be very advantageous for various applications, to produce proper system without barrier films i.e. with good electrical contact is still a challenge. The aim of the current work is to develop a cheap and easy method for growing carbon nanotubes forests on conductive substrate with the CCVD (Catalytic Chemical Vapor Deposition) technique at 640 °C. The applied catalyst contained Fe and Co and was deposited via dip coating onto an aluminum substrate. In order to control the height of CNT forest several parameters were varied during the both catalyst layer fabrication (e.g. ink concentration, ink composition, dipping speed) and the CCVD synthesis (e.g. gas feeds, reaction time). As-prepared CNT forests were investigated with various methods such as scanning electron microscopy, Raman spectroscopy, and cyclic voltammetry. With such an easy process it was possible to tune both the height and the quality of carbon nanotube forests.
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19
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Zhang L, He M, Hansen TW, Kling J, Jiang H, Kauppinen EI, Loiseau A, Wagner JB. Growth Termination and Multiple Nucleation of Single-Wall Carbon Nanotubes Evidenced by in Situ Transmission Electron Microscopy. ACS NANO 2017; 11:4483-4493. [PMID: 28402623 DOI: 10.1021/acsnano.6b05941] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
In order to controllably grow single-wall carbon nanotubes (SWCNTs), a better understanding of the growth processes and how they are influenced by external parameters such as catalyst and gaseous environment is required. Here, we present direct evidence of growth termination of individual SWCNTs and successive growth of additional SWCNTs on Co catalyst particles supported on MgO by means of environmental transmission electron microscopy. Such in situ observations reveal the plethora of solid carbon formations at the local scale while it is happening and thereby elucidate the multitude of configurations resulting from identical external synthesis conditions, which should be considered in the quest for controlled SWCNT growth. Using CO and a mixture of CO and H2 as carbon sources, we show that the growth of SWCNTs terminates with a reduced tube-catalyst adhesion strength. Two main reasons for the cessation are proposed: insufficient active carbon species and a certain amount of stress exerted at the tube-catalyst interface. Interestingly, it was observed that catalyst particles stayed active in terms of nucleating additional solid carbon structures after growth termination of the first SWCNT. These observations elucidate the importance of an in-depth understanding of the role of catalysts and carbon sources in the continued growth of SWCNTs. Furthermore, it serves as a guide for further control of carbon nanostructure synthesis via catalyst engineering and synthesis optimization.
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Affiliation(s)
- Lili Zhang
- Center for Electron Nanoscopy, Technical University of Denmark , Fysikvej 307, 2800, Kgs. Lyngby, Denmark
| | - Maoshuai He
- School of Materials Science and Engineering, Shandong University of Science and Technology , 266590 Qingdao, People's Republic of China
- Laboratoire d'Étude des Microstructures, ONERA-CNRS , BP 72, 92322 Châtillon CEDEX, France
| | - Thomas W Hansen
- Center for Electron Nanoscopy, Technical University of Denmark , Fysikvej 307, 2800, Kgs. Lyngby, Denmark
| | - Jens Kling
- Center for Electron Nanoscopy, Technical University of Denmark , Fysikvej 307, 2800, Kgs. Lyngby, Denmark
| | - Hua Jiang
- Department of Applied Physics, Aalto University School of Science , P.O. Box 15100, FI-00076 Aalto, Finland
| | - Esko I Kauppinen
- Department of Applied Physics, Aalto University School of Science , P.O. Box 15100, FI-00076 Aalto, Finland
| | - Annick Loiseau
- Laboratoire d'Étude des Microstructures, ONERA-CNRS , BP 72, 92322 Châtillon CEDEX, France
| | - Jakob B Wagner
- Center for Electron Nanoscopy, Technical University of Denmark , Fysikvej 307, 2800, Kgs. Lyngby, Denmark
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20
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Shi W, Li J, Polsen ES, Oliver CR, Zhao Y, Meshot ER, Barclay M, Fairbrother DH, Hart AJ, Plata DL. Oxygen-promoted catalyst sintering influences number density, alignment, and wall number of vertically aligned carbon nanotubes. NANOSCALE 2017; 9:5222-5233. [PMID: 28397885 DOI: 10.1039/c6nr09802a] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
A lack of synthetic control and reproducibility during vertically aligned carbon nanotube (CNT) synthesis has stifled many promising applications of organic nanomaterials. Oxygen-containing species are particularly precarious in that they have both beneficial and deleterious effects and are notoriously difficult to control. Here, we demonstrated diatomic oxygen's ability, independent of water, to tune oxide-supported catalyst thin film dewetting and influence nanoscale (diameter and wall number) and macro-scale (alignment and density) properties for as-grown vertically aligned CNTs. In particular, single- or few-walled CNT forests were achieved at very low oxygen loading, with single-to-multi-walled CNT diameters ranging from 4.8 ± 1.3 nm to 6.4 ± 1.1 nm over 0-800 ppm O2, and an expected variation in alignment, where both were related to the annealed catalyst morphology. Morphological differences were not the result of subsurface diffusion, but instead occurred via Ostwald ripening under several hundred ppm O2, and this effect was mitigated by high H2 concentrations and not due to water vapor (as confirmed in O2-free water addition experiments), supporting the importance of O2 specifically. Further characterization of the interface between the Fe catalyst and Al2O3 support revealed that either oxygen-deficit metal oxide or oxygen-adsorption on metals could be functional mechanisms for the observed catalyst nanoparticle evolution. Taken as a whole, our results suggest that the impacts of O2 and H2 on the catalyst evolution have been underappreciated and underleveraged in CNT synthesis, and these could present a route toward facile manipulation of CNT forest morphology through control of the reactive gaseous atmosphere alone.
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Affiliation(s)
- Wenbo Shi
- Department of Chemical and Environmental Engineering, Yale University, New Haven, CT, USA.
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21
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Lin YT, Singh R, Kuo SW, Ko FH. Bio-Inspired Supramolecular Chemistry Provides Highly Concentrated Dispersions of Carbon Nanotubes in Polythiophene. MATERIALS (BASEL, SWITZERLAND) 2016; 9:ma9060438. [PMID: 28773559 PMCID: PMC5456781 DOI: 10.3390/ma9060438] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 04/07/2016] [Revised: 05/17/2016] [Accepted: 05/27/2016] [Indexed: 06/07/2023]
Abstract
In this paper we report the first observation, through X-ray diffraction, of noncovalent uracil-uracil (U-U) dimeric π-stacking interactions in carbon nanotube (CNT)-based supramolecular assemblies. The directionally oriented morphology determined using atomic force microscopy revealed highly organized behavior through π-stacking of U moieties in a U-functionalized CNT derivative (CNT-U). We developed a dispersion system to investigate the bio-inspired interactions between an adenine (A)-terminated poly(3-adeninehexyl thiophene) (PAT) and CNT-U. These hybrid CNT-U/PAT materials interacted through π-stacking and multiple hydrogen bonding between the U moieties of CNT-U and the A moieties of PAT. Most importantly, the U···A multiple hydrogen bonding interactions between CNT-U and PAT enhanced the dispersion of CNT-U in a high-polarity solvent (DMSO). The morphology of these hybrids, determined using transmission electron microscopy, featured grape-like PAT bundles wrapped around the CNT-U surface; this tight connection was responsible for the enhanced dispersion of CNT-U in DMSO.
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Affiliation(s)
- Yen-Ting Lin
- Department of Materials Science and Engineering, National Chiao Tung University, 1001 University Road, Hsinchu 30010, Taiwan.
| | - Ranjodh Singh
- Department of Materials Science and Engineering, National Chiao Tung University, 1001 University Road, Hsinchu 30010, Taiwan.
| | - Shiao-Wei Kuo
- Department of Materials and Optoelectronic Science, National Sun Yat-Sen University, No. 70, Lienhai Road, Kaohsiung 80424, Taiwan.
| | - Fu-Hsiang Ko
- Department of Materials Science and Engineering, National Chiao Tung University, 1001 University Road, Hsinchu 30010, Taiwan.
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22
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Ding EX, Geng HZ, Wang J, Luo ZJ, Li G, Wang WY, Li LG, Yang HJ, Da SX, Wang J, Jiang H, Kauppinen EI. Hierarchical chrysanthemum-flower-like carbon nanomaterials grown by chemical vapor deposition. NANOTECHNOLOGY 2016; 27:085602. [PMID: 26808687 DOI: 10.1088/0957-4484/27/8/085602] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
Novel hierarchical chrysanthemum-flower-like carbon nanomaterials (CFL-CNMs) were synthesized by thermal chemical vapor deposition based on acetylene decomposition. A scanning electron microscope and a transmission electron microscope were employed to observe the morphology and structure of the unconventional nanostructures. It is found that the CFL-CNMs look like a blooming chrysanthemum with a stem rather than a spherical flower. The carbon flower has an average diameter of 5 μm, an average stem diameter of 150 nm, branch diameters ranging from 20 to 70 nm, and branch lengths ranging from 0.5 to 3 μm. The morphologies of the CFL-CNMs are unlike any of those previously reported. Fishbone-like carbon nanofibers with a spindle-shaped catalyst locating at the tip can also be found. Furthermore, the catalyst split was proposed to elucidate the formation mechanism of CFL-CNMs. A large and glomerate catalyst particle at the tip of the carbon nanofiber splits into smaller catalyst particles which are catalytic-active points for branch formation, resulting in the formation of CFL-CNMs.
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Affiliation(s)
- Er-Xiong Ding
- State Key Laboratory of Separation Membranes and Membrane Processes, School of Material Science and Engineering, Tianjin Polytechnic University, Tianjin 300387, People's Republic of China
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23
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Chen G, Davis RC, Futaba DN, Sakurai S, Kobashi K, Yumura M, Hata K. A sweet spot for highly efficient growth of vertically aligned single-walled carbon nanotube forests enabling their unique structures and properties. NANOSCALE 2016; 8:162-171. [PMID: 26619935 DOI: 10.1039/c5nr05537g] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
We investigated the correlation between growth efficiency and structural parameters of single-walled carbon nanotube (SWCNT) forests and report the existence of a SWCNT "sweet spot" in the CNT diameter and spacing domain for highly efficient synthesis. Only within this region could SWCNTs be grown efficiently. Through the investigation of the growth rates for ∼340 CNT forests spanning diameters from 1.3 to 8.0 nm and average spacing from 5 to 80 nm, this "sweet spot" was found to exist because highly efficient growth was constrained by several mechanistic boundaries that either hindered the formation or reduced the growth rate of SWCNT forests. Specifically, with increased diameter SWCNTs transitioned to multiwalled CNTs (multiwall border), small diameter SWCNTs could only be grown at low growth rates (low efficiency border), sparse SWCNTs lacked the requirements to vertically align (lateral growth border), and high density catalysts could not be prepared (high catalyst density border). As a result, the SWCNTs synthesized within this "sweet spot" possessed a unique set of characteristics vital for the development applications, such as large diameter, long, aligned, defective, and high specific surface area.
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Affiliation(s)
- Guohai Chen
- Technology Research Association for Single Wall Carbon Nanotubes (TASC), Central 5, 1-1-1 Higashi, Tsukuba, Ibaraki 305-8565, Japan and National Institute of Advanced Industrial Science and Technology (AIST), Central 5, 1-1-1- Higashi, Tsukuba, Ibaraki 305-8565, Japan.
| | - Robert C Davis
- Department of Physics and Astronomy, Brigham Young University, Provo, Utah 84602, USA
| | - Don N Futaba
- Technology Research Association for Single Wall Carbon Nanotubes (TASC), Central 5, 1-1-1 Higashi, Tsukuba, Ibaraki 305-8565, Japan and National Institute of Advanced Industrial Science and Technology (AIST), Central 5, 1-1-1- Higashi, Tsukuba, Ibaraki 305-8565, Japan.
| | - Shunsuke Sakurai
- Technology Research Association for Single Wall Carbon Nanotubes (TASC), Central 5, 1-1-1 Higashi, Tsukuba, Ibaraki 305-8565, Japan and National Institute of Advanced Industrial Science and Technology (AIST), Central 5, 1-1-1- Higashi, Tsukuba, Ibaraki 305-8565, Japan.
| | - Kazufumi Kobashi
- Technology Research Association for Single Wall Carbon Nanotubes (TASC), Central 5, 1-1-1 Higashi, Tsukuba, Ibaraki 305-8565, Japan and National Institute of Advanced Industrial Science and Technology (AIST), Central 5, 1-1-1- Higashi, Tsukuba, Ibaraki 305-8565, Japan.
| | - Motoo Yumura
- Technology Research Association for Single Wall Carbon Nanotubes (TASC), Central 5, 1-1-1 Higashi, Tsukuba, Ibaraki 305-8565, Japan and National Institute of Advanced Industrial Science and Technology (AIST), Central 5, 1-1-1- Higashi, Tsukuba, Ibaraki 305-8565, Japan.
| | - Kenji Hata
- Technology Research Association for Single Wall Carbon Nanotubes (TASC), Central 5, 1-1-1 Higashi, Tsukuba, Ibaraki 305-8565, Japan and National Institute of Advanced Industrial Science and Technology (AIST), Central 5, 1-1-1- Higashi, Tsukuba, Ibaraki 305-8565, Japan.
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24
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Wyss RM, Klare JE, Park HG, Noy A, Bakajin O, Lulevich V. Water-assisted growth of uniform 100 mm diameter SWCNT arrays. ACS APPLIED MATERIALS & INTERFACES 2014; 6:21019-21025. [PMID: 25408997 DOI: 10.1021/am505692a] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
We report a simple method for growing high-quality single-walled carbon nanotube (SWCNT) arrays on 100 mm wafers via the addition of water vapor to highly purified gases during the CNT growth step. We show that adding a small amount of water during growth helps to create a uniform catalyst distribution and yields high-quality (Raman G/D of 26 ± 3), high-density (up to 6 × 10(11) cm(-2)) and uniform SWCNT arrays on 100 mm large wafers. We rationalize our finding by suggesting that the addition of water decreases catalyst mobility, preventing its coarsening at higher temperatures. We also report a new mechanism of catalyst inactivation in wafer-scale growth using ultrapurified gas sources by the formation of large, 5 ± 3 μm iron particles. We found such formations to be common for substrates with large temperature gradients, such as for wafers processed in a typical cold-wall chemical vapor deposition reactor.
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Affiliation(s)
- Roman M Wyss
- Nanoscience for Energy Technology and Sustainability, Department of Mechanical and Process Engineering, ETH Zurich , Sonneggstrasse 3, Zürich CH-8092, Switzerland
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25
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Xiong G, Clark JN, Nicklin C, Rawle J, Robinson IK. Atomic diffusion within individual gold nanocrystal. Sci Rep 2014; 4:6765. [PMID: 25341377 PMCID: PMC4208027 DOI: 10.1038/srep06765] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2014] [Accepted: 08/28/2014] [Indexed: 11/13/2022] Open
Abstract
Due to their excess surface free energy and structural instabilities, nanoparticles exhibit interesting physical and chemical properties. There has been an ever-growing interest in investigating these properties, driven by the desire to further miniaturize electronic devices, develop new functional materials and catalysts. Here, the intriguing question of how diffusion evolves in a single nanoparticle is investigated by measuring the spatial and temporal variations of the diffracted coherent X-ray intensity during copper diffusion into a gold nanocrystal. Dislocation loops formed from the insertion of single layer of extra atoms between neighbouring gold host lattice planes are detected. Au-Cu alloy channels are found to penetrate the nanocrystal due to the differential diffusion rate along different directions. With the advent of higher brilliance sources and free-electron-lasers, Bragg Coherent X-ray Diffraction Imaging can play an important role in unveiling atomic behaviours in three dimensions for nanomaterials during various fundamental processes.
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Affiliation(s)
- Gang Xiong
- London Centre for Nanotechnology, University College London, London WC1H 0AH, UK
| | - Jesse N Clark
- London Centre for Nanotechnology, University College London, London WC1H 0AH, UK
| | - Chris Nicklin
- Diamond Light Source, Harwell Campus, Didcot, OX11 0DE, UK
| | - Jonathan Rawle
- Diamond Light Source, Harwell Campus, Didcot, OX11 0DE, UK
| | - Ian K Robinson
- 1] London Centre for Nanotechnology, University College London, London WC1H 0AH, UK [2] Research Complex at Harwell, Harwell Oxford, Didcot, OX11 0FA, UK
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26
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Sugime H, Esconjauregui S, D'Arsié L, Yang J, Makaryan T, Robertson J. Growth kinetics and growth mechanism of ultrahigh mass density carbon nanotube forests on conductive Ti/Cu supports. ACS APPLIED MATERIALS & INTERFACES 2014; 6:15440-15447. [PMID: 25126887 DOI: 10.1021/am504048h] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
We evaluate the growth kinetics and growth mechanism of ultrahigh mass density carbon nanotube forests. They are synthesized by chemical vapor deposition at 450 °C using a conductive Ti/Cu support and Co-Mo catalyst system. We find that Mo stabilizes Co particles preventing lift off during the initial growth stage, thus promoting the growth of ultrahigh mass density nanotube forests by the base growth mechanism. The morphology of the forest gradually changes with growth time, mostly because of a structural change of the catalyst particles. After 100 min growth, toward the bottom of the forest, the area density decreases from ∼ 3-6 × 10(11) cm(-2) to ∼ 5 × 10(10) cm(-2) and the mass density decreases from 1.6 to 0.38 g cm(-3). We also observe part of catalyst particles detached and embedded within nanotubes. The progressive detachment of catalyst particles results in the depletion of the catalyst metals on the substrate surfaces. This is one of the crucial reasons for growth termination and may apply to other catalyst systems where the same features are observed. Using the packed forest morphology, we demonstrate patterned forest growth with a pitch of ∼ 300 nm and a line width of ∼ 150 nm. This is one of the smallest patterning of the carbon nanotube forests to date.
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Affiliation(s)
- Hisashi Sugime
- Department of Engineering, University of Cambridge , Cambridge CB3 0FA, United Kingdom
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27
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Li J, Yang W, Ning J, Zhong Y, Hu Y. Rapid formation of Ag(n)X(X = S, Cl, PO4, C2O4) nanotubes via an acid-etching anion exchange reaction. NANOSCALE 2014; 6:5612-5615. [PMID: 24744113 DOI: 10.1039/c4nr00364k] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
This work presents a rapid nanotube fabrication method for a series of silver compounds AgnX, such as Ag2S, AgCl, Ag3PO4, and Ag2C2O4, from pregrown Ag2CO3 nanorod templates. The anion exchange process involved takes place in non-aqueous solutions just at room temperature and completes within 10 minutes. An acid-etching anion exchange reaction mechanism has been proved underneath the transformation process from Ag2CO3 nanorods to AgnX nanotubes by the observation of an intermediate yolk-shell nanostructure. It has been found that the final structure of the products can be conveniently controlled by simply varying the concentration of HnX acids, and the organic solvents employed play a vital role in the formation of the nanotubes by effectively controlling the diffusion rates of different species of reacting ions. As a demonstration, the as-prepared AgCl and Ag3PO4 nanotubes exhibit enhanced photocatalytic activity and favorable recyclability for the photodegradation of rhodamine B (RhB) under visible-light irradiation.
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Affiliation(s)
- Jingjing Li
- Key Laboratory of the Ministry of Education for Advanced Catalysis Materials, Institute of Physical Chemistry, Zhejiang Normal University, Jinhua, 321004, P. R. China.
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Boncel S, Pattinson SW, Geiser V, Shaffer MSP, Koziol KKK. En route to controlled catalytic CVD synthesis of densely packed and vertically aligned nitrogen-doped carbon nanotube arrays. BEILSTEIN JOURNAL OF NANOTECHNOLOGY 2014; 5:219-33. [PMID: 24605289 PMCID: PMC3944053 DOI: 10.3762/bjnano.5.24] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/29/2013] [Accepted: 02/05/2014] [Indexed: 05/24/2023]
Abstract
The catalytic chemical vapour deposition (c-CVD) technique was applied in the synthesis of vertically aligned arrays of nitrogen-doped carbon nanotubes (N-CNTs). A mixture of toluene (main carbon source), pyrazine (1,4-diazine, nitrogen source) and ferrocene (catalyst precursor) was used as the injection feedstock. To optimize conditions for growing the most dense and aligned N-CNT arrays, we investigated the influence of key parameters, i.e., growth temperature (660, 760 and 860 °C), composition of the feedstock and time of growth, on morphology and properties of N-CNTs. The presence of nitrogen species in the hot zone of the quartz reactor decreased the growth rate of N-CNTs down to about one twentieth compared to the growth rate of multi-wall CNTs (MWCNTs). As revealed by electron microscopy studies (SEM, TEM), the individual N-CNTs (half as thick as MWCNTs) grown under the optimal conditions were characterized by a superior straightness of the outer walls, which translated into a high alignment of dense nanotube arrays, i.e., 5 × 10(8) nanotubes per mm(2) (100 times more than for MWCNTs grown in the absence of nitrogen precursor). In turn, the internal crystallographic order of the N-CNTs was found to be of a 'bamboo'-like or 'membrane'-like (multi-compartmental structure) morphology. The nitrogen content in the nanotube products, which ranged from 0.0 to 3.0 wt %, was controlled through the concentration of pyrazine in the feedstock. Moreover, as revealed by Raman/FT-IR spectroscopy, the incorporation of nitrogen atoms into the nanotube walls was found to be proportional to the number of deviations from the sp(2)-hybridisation of graphene C-atoms. As studied by XRD, the temperature and the [pyrazine]/[ferrocene] ratio in the feedstock affected the composition of the catalyst particles, and hence changed the growth mechanism of individual N-CNTs into a 'mixed base-and-tip' (primarily of the base-type) type as compared to the purely 'base'-type for undoped MWCNTs.
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Affiliation(s)
- Slawomir Boncel
- Department of Organic Chemistry, Biochemistry and Biotechnology, Silesian University of Technology, Krzywoustego 4, 44-100 Gliwice, Poland
| | - Sebastian W Pattinson
- Department of Materials Science and Metallurgy, University of Cambridge, 27 Charles Babbage Road, Cambridge CB3 0FS, United Kingdom
| | - Valérie Geiser
- Department of Materials Science and Metallurgy, University of Cambridge, 27 Charles Babbage Road, Cambridge CB3 0FS, United Kingdom
| | - Milo S P Shaffer
- Imperial College London, Department of Chemistry, London SW7 2AZ, United Kingdom
| | - Krzysztof K K Koziol
- Department of Materials Science and Metallurgy, University of Cambridge, 27 Charles Babbage Road, Cambridge CB3 0FS, United Kingdom
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Ham H, Park NH, Kim SS, Kim HW. Evidence of Ostwald ripening during evolution of micro-scale solid carbon spheres. Sci Rep 2014; 4:3579. [PMID: 24389995 PMCID: PMC3880962 DOI: 10.1038/srep03579] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2013] [Accepted: 12/04/2013] [Indexed: 11/18/2022] Open
Abstract
Ostwald ripening is an evolutionary mechanism that results in micro-scale carbon spheres from nano-scale spheres. Vapor-phase carbon elements from small carbon nanoparticles are transported to the surface of submicron-scale carbon spheres, eventually leading to their evolution to micro-scale spheres via well-known growth mechanisms, including the layer-by-layer, island, and mixed growth modes. The results obtained from this work will pave the way to the disclosure of the evolutionary mechanism of micro-scale carbon spheres and open a new avenue for practical applications.
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Affiliation(s)
- Heon Ham
- H&H Co. Ltd., Korea National University of Transportation, 50 Daehak-ro, Chungju-si, Chungbuk 330-702, Republic of Korea
| | - No-Hyung Park
- Department of Textile Convergence of Biotechnology & Nanotechnology, Korea Institute of Industrial Technology 1271-18 Sa 3-dong, Sangnok-gu, Ansan-si, Gyeonggi-do, 426-910, Republic of Korea
| | - Sang Sub Kim
- Department of Materials Science and Engineering, Inha University, Incheon 402-751, Republic of Korea
| | - Hyoun Woo Kim
- Division of Materials Science and Engineering, Hanyang University, Seoul 133-791, Republic of Korea
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Shawat E, Mor V, Oakes L, Fleger Y, Pint CL, Nessim GD. What is below the support layer affects carbon nanotube growth: an iron catalyst reservoir yields taller nanotube carpets. NANOSCALE 2014; 6:1545-1551. [PMID: 24323364 DOI: 10.1039/c3nr05240k] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
Here we demonstrate an approach to enhance the growth of vertically aligned carbon nanotubes (CNTs) by including a catalyst reservoir underneath the thin-film alumina catalyst underlayer. This reservoir led to enhanced CNT growth due to the migration of catalytic material from below the underlayer up to the surface through alumina pinholes during processing. This led to the formation of large Fe particles, which in turn influenced the morphology evolution of the catalytic iron surface layer through Ostwald ripening. With inclusion of this catalyst reservoir, we observed CNT growth up to 100% taller than that observed without the catalyst reservoir consistently across a wide range of annealing and growth durations. Imaging studies of catalyst layers both for different annealing times and for different alumina support layer thicknesses demonstrate that the surface exposure of metal from the reservoir leads to an active population of smaller catalyst particles upon annealing as opposed to a bimodal catalyst size distribution that appears without inclusion of a reservoir. Overall, the mechanism for growth enhancement we present here demonstrates a new route to engineering efficient catalyst structures to overcome the limitations of CNT growth processes.
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Affiliation(s)
- E Shawat
- Department of Chemistry and Institute for Nanotechnology, Bar-Ilan University, Ramat Gan, 52900, Israel.
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Wu HS, Guo C, Jia J, Rosenthal U, Jiao H. Strain-free [N]ferrocenylenes and cyclo[10]ferrocenylene. Chemphyschem 2013; 14:3902-5. [PMID: 24273062 DOI: 10.1002/cphc.201300706] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2013] [Revised: 08/28/2013] [Indexed: 11/11/2022]
Abstract
Calculated attraction: Trans-linear and cis-angular [N]ferrocenylenes, as well as cyclo[10]ferrocenylene, higher homologues of biferrocenylene, and analogues of [N]phenylenes, are demonstrated as strain-free.
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Affiliation(s)
- Hai-Shun Wu
- School of Chemistry and Materials Science, Shanxi Normal University, Linfen 041004 (PR China).
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Controlled fabrication of PANI/CNF hybrid films: Molecular interaction induced various micromorphologies and electrochemical properties. J Colloid Interface Sci 2013; 411:204-12. [DOI: 10.1016/j.jcis.2013.08.024] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2013] [Revised: 08/04/2013] [Accepted: 08/11/2013] [Indexed: 11/19/2022]
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Chen G, Futaba DN, Kimura H, Sakurai S, Yumura M, Hata K. Absence of an ideal single-walled carbon nanotube forest structure for thermal and electrical conductivities. ACS NANO 2013; 7:10218-10224. [PMID: 24090543 DOI: 10.1021/nn404504f] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/02/2023]
Abstract
We report the fundamental dependence of thermal diffusivity and electrical conductance on the diameter and defect level for vertically aligned single-walled carbon nanotube (SWCNT) forests. By synthesizing a series of SWCNT forests with continuous control of the diameter and defect level over a wide range while holding all other structures fixed, we found an inverse and mutually exclusive relationship between the thermal diffusivity and the electrical conductance. This relationship was explained by the differences in the fundamental mechanisms governing each property and the optimum required structures. We concluded that high thermal diffusivity and electrical conductance would be extremely difficult to simultaneously achieve by a single SWCNT forest structure within current chemical vapor deposition synthetic technology, and the "ideal" SWCNT forest structure would differ depending on application.
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Affiliation(s)
- Guohai Chen
- Technology Research Association for Single Wall Carbon Nanotubes (TASC) , Central 5, 1-1-1 Higashi, Tsukuba, Ibaraki 305-8565, Japan
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Sakurai S, Inaguma M, Futaba DN, Yumura M, Hata K. Diameter and density control of single-walled carbon nanotube forests by modulating Ostwald ripening through decoupling the catalyst formation and growth processes. SMALL (WEINHEIM AN DER BERGSTRASSE, GERMANY) 2013; 9:3584-3592. [PMID: 23625816 DOI: 10.1002/smll.201300223] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/22/2013] [Indexed: 06/02/2023]
Abstract
A continuous and wide range control of the diameter (1.9-3.2 nm) and density (0.03-0.11 g cm(-3) ) of single-walled carbon nanotube (SWNT) forests is demonstrated by decoupling the catalyst formation and SWNT growth processes. Specifically, by managing the catalyst formation temperature and H2 exposure, the redistribution of the Fe catalyst thin film into nanoparticles is controlled while a fixed growth condition preserved the growth yield. The diameter and density are inversely correlated, where low/high density forests would consist of large/small diameter SWNTs, which is proposed as a general rule for the structural control of SWNT forests. The catalyst formation process is modeled by considering the competing processes, Ostwald ripening, and subsurface diffusion, where the dominant mechanism is found to be Ostwald ripening. Specifically, H2 exposure increases catalyst surface energy and decreases diameter, while increased temperature leads to increased diffusion on the surface and an increase in diameter.
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Affiliation(s)
- Shunsuke Sakurai
- Nanotube Research Center, National Institute of Advanced Industrial Science and Technology (AIST), Central 5, 1-1-1, Higashi, Tsukuba, Ibaraki, 305-8565, Japan; Technology Research Association for Single Wall Carbon Nanotubes (TASC), Central 5, 1-1-1 Higashi, Tsukuba, Ibaraki, 305-8565, Japan
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A Fundamental Limitation of Small Diameter Single-Walled Carbon Nanotube Synthesis-A Scaling Rule of the Carbon Nanotube Yield with Catalyst Volume. MATERIALS 2013; 6:2633-2641. [PMID: 28811399 PMCID: PMC5521222 DOI: 10.3390/ma6072633] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/29/2013] [Revised: 06/18/2013] [Accepted: 06/24/2013] [Indexed: 11/25/2022]
Abstract
Understanding the fundamental mechanisms and limiting processes of the growth of single-walled carbon nanotube (SWCNT) would serve as a guide to achieve further control on structural parameters of SWCNT. In this paper, we have studied the growth kinetics of a series of SWCNT forests continuously spanning a wide range of diameters (1.9–3.2 nm), and have revealed an additional fundamental growth limiting process where the mass of the individual SWCNT is determined by the individual catalyst volume. Calculation of the conversion rate of carbon atoms into CNTs per Fe atom is 2 × 102 atoms per second. This rate limiting process provides an important understanding where the larger diameter SWCNT would grow faster, and thus be more suited for mass production.
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Van Hooijdonk E, Bittencourt C, Snyders R, Colomer JF. Functionalization of vertically aligned carbon nanotubes. BEILSTEIN JOURNAL OF NANOTECHNOLOGY 2013; 4:129-52. [PMID: 23504581 PMCID: PMC3596098 DOI: 10.3762/bjnano.4.14] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/29/2012] [Accepted: 01/30/2013] [Indexed: 05/06/2023]
Abstract
This review focuses and summarizes recent studies on the functionalization of carbon nanotubes oriented perpendicularly to their substrate, so-called vertically aligned carbon nanotubes (VA-CNTs). The intrinsic properties of individual nanotubes make the VA-CNTs ideal candidates for integration in a wide range of devices, and many potential applications have been envisaged. These applications can benefit from the unidirectional alignment of the nanotubes, the large surface area, the high carbon purity, the outstanding electrical conductivity, and the uniformly long length. However, practical uses of VA-CNTs are limited by their surface characteristics, which must be often modified in order to meet the specificity of each particular application. The proposed approaches are based on the chemical modifications of the surface by functionalization (grafting of functional chemical groups, decoration with metal particles or wrapping of polymers) to bring new properties or to improve the interactions between the VA-CNTs and their environment while maintaining the alignment of CNTs.
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Affiliation(s)
- Eloise Van Hooijdonk
- Research center in Physics of Matter and Radiation, University of Namur, Namur, Belgium
| | - Carla Bittencourt
- Chimie des Interactions Plasma-Surface, Research Institute for Materials Science and Engineering, University of Mons, Mons, Belgium
| | - Rony Snyders
- Chimie des Interactions Plasma-Surface, Research Institute for Materials Science and Engineering, University of Mons, Mons, Belgium
- Materia Nova Research Center, Mons, Belgium
| | - Jean-François Colomer
- Research center in Physics of Matter and Radiation, University of Namur, Namur, Belgium
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37
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Youn SK, Yazdani N, Patscheider J, Park HG. Facile diameter control of vertically aligned, narrow single-walled carbon nanotubes. RSC Adv 2013. [DOI: 10.1039/c2ra22392a] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023] Open
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38
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Meng G, Yanagida T, Kanai M, Suzuki M, Nagashima K, Xu B, Zhuge F, Klamchuen A, He Y, Rahong S, Kai S, Kawai T. Pressure-induced evaporation dynamics of gold nanoparticles on oxide substrate. PHYSICAL REVIEW. E, STATISTICAL, NONLINEAR, AND SOFT MATTER PHYSICS 2013; 87:012405. [PMID: 23410342 DOI: 10.1103/physreve.87.012405] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/11/2012] [Indexed: 05/27/2023]
Abstract
Here we report thermal evaporation dynamics of Au nanoparticles on single crystal oxide substrates, including MgO, SrTiO(3), and Al(2)O(3). The size reduction rate of Au nanoparticles via thermal treatments is strongly dependent on not only temperature but also pressure. Lowering the pressure of inert Ar gas from 10(5) to 10 Pa increases the size reduction rate over 30 times in the temperature range 800 °C-950 °C. The temperature dependence is solely due to the variation of saturated vapor pressure of Au, whereas the pressure dependence of the surrounding inert gas can be interpreted in terms of a pressure dependence on a gas-phase diffusion of evaporated Au atoms into the surroundings. We present a simplified model to explain an evaporation dynamics, which well describes the pressure dependence on a size reduction rate of Au nanoparticles. By utilizing this useful pressure-induced evaporation dynamics, we succeeded in manipulating a size reduction of Au nanoparticle arrays down to -10 nm diameter range from -300 nm initial size by programming sequentially a surrounding pressure.
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Affiliation(s)
- Gang Meng
- The Institute of Scientific and Industrial Research, Osaka University, 8-1 Mihogaoka Ibaraki, Osaka, 567-0047, Japan
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Xiang R, Einarsson E, Murakami Y, Shiomi J, Chiashi S, Tang Z, Maruyama S. Diameter modulation of vertically aligned single-walled carbon nanotubes. ACS NANO 2012; 6:7472-9. [PMID: 22812723 DOI: 10.1021/nn302750x] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/07/2023]
Abstract
We demonstrate wide-range diameter modulation of vertically aligned single-walled carbon nanotubes (SWNTs) using a wet chemistry prepared catalyst. In order to ensure compatibility to electronic applications, the current minimum mean diameter of 2 nm for vertically aligned SWNTs is challenged. The mean diameter is decreased to about 1.4 nm by reducing Co catalyst concentrations to 1/100 or by increasing Mo catalyst concentrations by five times. We also propose a novel spectral analysis method that allows one to distinguish absorbance contributions from the upper, middle, and lower parts of a nanotube array. We use this method to quantitatively characterize the slight diameter change observed along the array height. On the basis of further investigation of the array and catalyst particles, we conclude that catalyst aggregation-rather than Ostwald ripening-dominates the growth of metal particles.
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Affiliation(s)
- Rong Xiang
- State Key Laboratory of Optoelectronic Materials and Technologies, School of Physics and Engineering, Sun Yat-Sen University, Guangzhou 510275, China.
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Li HH, Zhang P, Liang CL, Yang J, Zhou M, Lu XH, Hope GA. Facile electrochemical synthesis of tellurium nanorods and their photoconductive properties. CRYSTAL RESEARCH AND TECHNOLOGY 2012. [DOI: 10.1002/crat.201200273] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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