1
|
Zheng B, Qiao L, Yu HT, Wang QY, Xie Y, Qu CQ. Enhanced field-emission properties of buckled α-borophene by means of Li decoration: a first-principles investigation. Phys Chem Chem Phys 2018; 20:15139-15148. [PMID: 29789848 DOI: 10.1039/c8cp01048j] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
In this study, the structures and field-emission properties of Li-decorated buckled α-borophene (BBP) were investigated by first-principles density functional theory at the PW91 level. Using the computed binding energies, Hirshfeld- and electrostatic potential-derived charges, induced dipole moments, densities of states, and ionization potentials, we evaluated the influence of an applied electric field on the structural stability, work function, and field-emission current of the Li-decorated BBP nanostructures. Furthermore, we also explored the quantitative dependence of the emission current on the electric field, Li concentration, and molecular orbitals. The computed results indicated that increasing the electric field and Li concentration has a considerably positive effect on the field-emission performance of the Li-decorated BBPs. Besides advantages including small work functions and low ionization potentials, most remarkably, the field-emission current can be as high as 48.81 μA in Li4/BBP (supercell with 36 atoms only) under a rather small applied electric field of 0.05 V Å-1, which rivals the highest value of the graphene-BN nanocomposite among all the theoretical nanostructures presented to date. Our results highly support the fact that Li-decorated BBPs can be appealing field-emission cathode materials with an extremely high emission current.
Collapse
Affiliation(s)
- Bing Zheng
- Key Laboratory of Functional Inorganic Material Chemistry (Ministry of Education) and School of Chemistry and Materials Science, Heilongjiang University, Harbin 150080, P. R. China.
| | | | | | | | | | | |
Collapse
|
2
|
Saedi L, Jameh-bozorghi S, Maskanati M, Soleymanabadi H. The effect of water on the electronic and field emission properties of inorganic AlN nanocones: Computational study. INORG CHEM COMMUN 2018; 90:86-91. [DOI: 10.1016/j.inoche.2018.02.011] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
|
3
|
|
4
|
Sun L, Zhou X, Lin Z, Guo T, Zhang Y, Zeng Y. Effects of ZnO Quantum Dots Decoration on the Field Emission Behavior of Graphene. ACS Appl Mater Interfaces 2016; 8:31856-31862. [PMID: 27797469 DOI: 10.1021/acsami.6b10454] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
ZnO quantum dots (QDs) have been decorated on graphene deposited on patterned Ag electrodes as a field emission cathode by a solution process. Effects of ZnO QDs on the field emission behavior of graphene are studied by experiment and first-principles calculations. The results indicate that the attachment of ZnO QDs with a C atom leads to the enhancement of electron emission from graphene, which is mainly attributed to the reduction of the work function and ionization potential, and the increase of the Fermi level of graphene after the decoration. A change in the local density distribution and the density of states near the Fermi level may also account for this behavior. Our study may help to develop new field emission composites and expand ZnO QDs in applications for electron emission devices as well.
Collapse
Affiliation(s)
- Lei Sun
- National & Local United Engineer Laboratory of Flat Panel Display Technology, Fuzhou University , 350002 Fuzhou, China
- Zhicheng College, Fuzhou University , 350002 Fuzhou, China
| | - Xiongtu Zhou
- National & Local United Engineer Laboratory of Flat Panel Display Technology, Fuzhou University , 350002 Fuzhou, China
| | - Zhixian Lin
- National & Local United Engineer Laboratory of Flat Panel Display Technology, Fuzhou University , 350002 Fuzhou, China
| | - Tailiang Guo
- National & Local United Engineer Laboratory of Flat Panel Display Technology, Fuzhou University , 350002 Fuzhou, China
| | - Yongai Zhang
- National & Local United Engineer Laboratory of Flat Panel Display Technology, Fuzhou University , 350002 Fuzhou, China
| | - Yongzhi Zeng
- National & Local United Engineer Laboratory of Flat Panel Display Technology, Fuzhou University , 350002 Fuzhou, China
| |
Collapse
|
5
|
Otsuka K, Inoue T, Shimomura Y, Chiashi S, Maruyama S. Field emission and anode etching during formation of length-controlled nanogaps in electrical breakdown of horizontally aligned single-walled carbon nanotubes. Nanoscale 2016; 8:16363-16370. [PMID: 27714089 DOI: 10.1039/c6nr05449h] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
We observe field emission between nanogaps and voltage-driven gap extension of single-walled carbon nanotubes (SWNTs) on substrates during the electrical breakdown process. Experimental results show that the gap size is dependent on the applied voltage and humidity, which indicates high controllability of the gap size by appropriate adjustment of these parameters in accordance with the application. We propose a mechanism for the gap formation during electrical breakdown as follows. After small gaps are formed by Joule heating-induced oxidation, SWNTs on the anode side are electrochemically etched due to physically-adsorbed water from the air and the enhanced electric field at the SWNT tips. Field emission is measured in a vacuum as a possible mechanism for charge transfer at SWNT gaps. The relationship between the field enhancement factor and geometric features of SWNTs explains both the voltage dependence of the extended gap size and the field emission properties of the SWNT gaps. In addition, the similar field-induced etching can cause damage to adjacent SWNTs, which possibly deteriorates the selectivity for cutting metallic pathways in the presence of water vapor.
Collapse
Affiliation(s)
- Keigo Otsuka
- Department of Mechanical Engineering, The University of Tokyo, Tokyo 113-8656, Japan.
| | - Taiki Inoue
- Department of Mechanical Engineering, The University of Tokyo, Tokyo 113-8656, Japan.
| | - Yuki Shimomura
- Department of Mechanical Engineering, The University of Tokyo, Tokyo 113-8656, Japan.
| | - Shohei Chiashi
- Department of Mechanical Engineering, The University of Tokyo, Tokyo 113-8656, Japan.
| | - Shigeo Maruyama
- Department of Mechanical Engineering, The University of Tokyo, Tokyo 113-8656, Japan. and Energy NanoEngineering Lab., National Institute of Advanced Industrial Science and Technology (AIST), Ibaraki 305-8564, Japan
| |
Collapse
|
6
|
Abstract
An innovative hydrogen sensing concept is demonstrated based on the field emission from multi-walled carbon nanotubes, where the low emission currents rise in proportion to hydrogen partial pressures above 10(-9) Torr. Experimental and first principles studies reveal that the sensing mechanism is attributed to the effective work function reduction from dissociative hydrogen chemisorption. The embedded Ni catalyst would assist both the hydrogen dissociation and work function reduction. This technique is promising to build miniature low cost hydrogen sensors for multiple applications. This work is valuable for studies of nanocarbon-gas reaction mechanisms and the work function properties in adsorption related applications, including field emission, hydrogen storage, energy cells, and gas sensing.
Collapse
Affiliation(s)
- Changkun Dong
- Institute of Micro-nano Structures & Optoelectronics, Wenzhou University, Wenzhou, Zhejiang 325035, P. R. China.
| | - Haijun Luo
- Institute of Micro-nano Structures & Optoelectronics, Wenzhou University, Wenzhou, Zhejiang 325035, P. R. China.
| | - Jianqiu Cai
- Institute of Micro-nano Structures & Optoelectronics, Wenzhou University, Wenzhou, Zhejiang 325035, P. R. China.
| | - Fuquan Wang
- Institute of Micro-nano Structures & Optoelectronics, Wenzhou University, Wenzhou, Zhejiang 325035, P. R. China.
| | - Yangyang Zhao
- Institute of Micro-nano Structures & Optoelectronics, Wenzhou University, Wenzhou, Zhejiang 325035, P. R. China.
| | - Detian Li
- Science and Technology on Vacuum & Cryogenics Technology and Physics Laboratory, Lanzhou Institute of Physics, Lanzhou, Gansu 730000, P. R. China
| |
Collapse
|
7
|
|
8
|
Deng JH, Cheng L, Wang FJ, Li GZ, Li DJ, Cheng GA. High current density and longtime stable field electron transfer from large-area densely arrayed graphene nanosheet-carbon nanotube hybrids. ACS Appl Mater Interfaces 2014; 6:21558-21566. [PMID: 25335851 DOI: 10.1021/am5065624] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
Achieving high current and longtime stable field emission from large area (larger than 1 mm(2)), densely arrayed emitters is of great importance in applications for vacuum electron sources. We report here the preparation of graphene nanosheet-carbon nanotube (GNS-CNT) hybrids by following a process of iron ion prebombardment on Si wafers, catalyst-free growth of GNSs on CNTs, and high-temperature annealing. Structural observations indicate that the iron ion prebombardment influences the growth of CNTs quite limitedly, and the self-assembled GNSs sparsely distributed on the tips of CNTs with their sharp edges unfolded outside. The field emission study indicates that the maximum emission current density (Jmax) is gradually promoted after these treatments, and the composition with GNSs is helpful for decreasing the operation fields of CNTs. An optimal Jmax up to 85.10 mA/cm(2) is achieved from a 4.65 mm(2) GNS-CNT sample, far larger than 7.41 mA/cm(2) for the as-grown CNTs. This great increase of Jmax is ascribed to the reinforced adhesion of GNS-CNT hybrids to substrates. We propose a rough calculation and find that this adhesion is promoted by 7.37 times after the three-step processing. We consider that both the ion prebombardment produced rough surface and the wrapping of CNT foot by catalyst residuals during thermal processing are responsible for this enhanced adhesion. Furthermore, the three-step prepared GNS-CNT hybrids present excellent field emission stability at high emission current densities (larger than 20 mA/cm(2)) after being perfectly aged.
Collapse
Affiliation(s)
- Jian-Hua Deng
- College of Physics and Materials Science, Tianjin Normal University , Tianjin 300387, People's Republic of China
| | | | | | | | | | | |
Collapse
|
9
|
|
10
|
Deng JH, Hou XG, Cheng L, Wang FJ, Yu B, Li GZ, Li DJ, Cheng GA, Wu S. Irradiation damage determined field emission of ion irradiated carbon nanotubes. ACS Appl Mater Interfaces 2014; 6:5137-5143. [PMID: 24621129 DOI: 10.1021/am500370b] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
Figuring out the underlying relationship between the field emission (FE) properties and the ion irradiation induced structural change of carbon nanotubes (CNTs) is of great importance in developing high-performance field emitters. We report here the FE properties of Si and C ion irradiated CNTs with different irradiation doses. It is found that the FE performance of the ion irradiated CNTs ameliorates before and deteriorates after an irradiation-ion-species related dose. The improved FE properties are ascribed to the increased amount of defects, while the degraded FE performance is attributed to the great shape change of CNTs. These two structural changes are further characterized by a structural damage related parameter: dpa (displacement per atom), and the FE performance of the ion irradiated CNTs is surprisingly found to be mainly dependent on the dpa. The optimal dpa for FE of the ion irradiated CNTs is ∼0.60. We ascribe this to the low irradiation doses and the low substrate temperature that make the ion irradiation play a more important role in producing defects rather than element doping. Furthermore, the ion irradiated CNTs exhibit excellent FE stability, showing promising prospects in practical applications.
Collapse
Affiliation(s)
- Jian-Hua Deng
- College of Physics and Materials Science, Tianjin Normal University , Tianjin 300387, People's Republic of China
| | | | | | | | | | | | | | | | | |
Collapse
|
11
|
|
12
|
Deng JH, Yu B, Li GZ, Hou XG, Zhao ML, Li DJ, Zheng RT, Cheng GA. Self-assembled growth of multi-layer graphene on planar and nano-structured substrates and its field emission properties. Nanoscale 2013; 5:12388-12393. [PMID: 24162073 DOI: 10.1039/c3nr04145j] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/02/2023]
Abstract
Vertical multi-layer graphenes (MLGs) have been synthesized without a catalyst on planar and nano-structured substrates by using microwave plasma enhanced chemical vapor deposition. The growth of MLGs on non-carbon substrates is quite different from that on carbon-based substrates. It starts with a pre-deposition of a carbon buffer layer to achieve a homo-epitaxial growth. The nucleation and growth of MLGs was found to be strongly influenced by the surface geometry and topography of substrates. Planar substrates suitable for atom diffusion are favorable for growing large-scale MLGs, and defect-rich substrates are beneficial for quick MLG nucleation and thus the growth of densely distributed MLGs. The field emission properties of MLGs grown on planar and nano-structured substrates were studied and are found to be strongly dependent on the nature of substrates. Substrates having good conductivity and large aspect ratios such as carbon nanotubes (CNTs) have good field emission properties. The best field emission properties of MLG/CNT composites with optimal shapes were observed with a low turn-on electric field of 0.93 V μm(-1), a threshold field of 1.56 V μm(-1), a maximum emission current density of 60.72 mA cm(-2), and excellent stability.
Collapse
Affiliation(s)
- Jian-Hua Deng
- College of Physics and Materials Science, Tianjin Normal University, Tianjin 300387, P. R. China.
| | | | | | | | | | | | | | | |
Collapse
|
13
|
Lee S, Lee M, Chung YC. Enhanced hydrogen storage properties under external electric fields of N-doped graphene with Li decoration. Phys Chem Chem Phys 2013; 15:3243-8. [DOI: 10.1039/c2cp44231k] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
|
14
|
CHATTERJEE A. Industrial Application of Reactivity Indices within Density Functional Theory. J Comput Chem Jpn 2013. [DOI: 10.2477/jccj.2012-0016] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
|
15
|
LAKSHMI I, SILAMBARASAN D, SURYA VJ, RAJARAJESWARI M, IYAKUTTI K, MIZUSEKI H, KAWAZOE Y. COMPUTATION OF INTERACTION POTENTIAL OF ADSORBATES ON ZIGZAG SWCNTs — APPLICATION TO FUNCTIONALIZATION AND HYDROGEN STORAGE. Int J Nanosci 2012. [DOI: 10.1142/s0219581x11008125] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
Nature of the interaction potential of different adsorbates on different zigzag single-walled carbon nanotubes is investigated. The intermolecular potentials for H2 absorbed in carbon nanotubes (5, 0), (6, 0), (7, 0), (8, 0), (9, 0), and (10, 0) are computed and sketched. This study is extended to N2 adsorbed on (4, 0) and BH3 adsorbed on (10, 0) tubes. The equilibrium positions of the adsorbates obtained from the potential model serve as an initial guess in designing the CNT + adsorbate complex in the simulation cell and this process considerably reduces the computation time. Further, the hydrogen storage capacity of CNT(10,0) + BH3 complex is calculated. The estimated storage capacity of this system is in the range 6–12 wt.%.
Collapse
Affiliation(s)
- I. LAKSHMI
- Department of Computer Science, Jothi Nivas College for Women, Bangalore — 560095, Karnataka, India
| | - D. SILAMBARASAN
- School of Physics, Madurai Kamaraj University, Madurai — 625021, Tamil Nadu, India
| | - V. J. SURYA
- School of Physics, Madurai Kamaraj University, Madurai — 625021, Tamil Nadu, India
| | - M. RAJARAJESWARI
- School of Physics, Madurai Kamaraj University, Madurai — 625021, Tamil Nadu, India
| | - K. IYAKUTTI
- School of Physics, Madurai Kamaraj University, Madurai — 625021, Tamil Nadu, India
| | - H. MIZUSEKI
- Institute for Materials Research, Tohoku University, Sendai — 980-8577, Japan
| | - Y. KAWAZOE
- Institute for Materials Research, Tohoku University, Sendai — 980-8577, Japan
| |
Collapse
|
16
|
Liao Q, Qin Z, Zhang Z, Qi J, Zhang Y, Huang Y, Liu L. Investigation on the Plasma-Induced Emission Properties of Large Area Carbon Nanotube Array Cathodes with Different Morphologies. Nanoscale Res Lett 2011; 6:40. [PMID: 27502662 PMCID: PMC3211494 DOI: 10.1007/s11671-010-9784-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 06/22/2010] [Accepted: 09/09/2010] [Indexed: 06/06/2023]
Abstract
Large area well-aligned carbon nanotube (CNT) arrays with different morphologies were synthesized by using a chemical vapor deposition. The plasma-induced emission properties of CNT array cathodes with different morphologies were investigated. The ratio of CNT height to CNT-to-CNT distance has considerable effects on their plasma-induced emission properties. As the ratio increases, emission currents of CNT array cathodes decrease due to screening effects. Under the pulse electric field of about 6 V/μm, high-intensity electron beams of 170-180 A/cm(2) were emitted from the surface plasma. The production mechanism of the high-intensity electron beams emitted from the CNT arrays was plasma-induced emission. Moreover, the distribution of the electron beams was in situ characterized by the light emission from the surface plasma.
Collapse
Affiliation(s)
- Qingliang Liao
- State Key Laboratory for Advanced Metals and Materials, Department of Materials Physics, University of Science and Technology Beijing, 100083, Beijing, China
| | - Zi Qin
- State Key Laboratory for Advanced Metals and Materials, Department of Materials Physics, University of Science and Technology Beijing, 100083, Beijing, China
| | - Zheng Zhang
- State Key Laboratory for Advanced Metals and Materials, Department of Materials Physics, University of Science and Technology Beijing, 100083, Beijing, China
| | - Junjie Qi
- State Key Laboratory for Advanced Metals and Materials, Department of Materials Physics, University of Science and Technology Beijing, 100083, Beijing, China
| | - Yue Zhang
- State Key Laboratory for Advanced Metals and Materials, Department of Materials Physics, University of Science and Technology Beijing, 100083, Beijing, China.
| | - Yunhua Huang
- State Key Laboratory for Advanced Metals and Materials, Department of Materials Physics, University of Science and Technology Beijing, 100083, Beijing, China
| | - Liang Liu
- Department of Physics, Tsinghua-Foxconn Nanotechnology Research Center, Tsinghua University, 100084, Beijing, China
| |
Collapse
|
17
|
Abstract
We have studied the intense electron beams emitted from multiple metallic, vertical and well-aligned Carbon Nanotube (CNT) field emitters. A two-dimensional (2D) particle-in-cell simulation code MAGIC2D is used to obtain the I–V characteristics near to the apex of the emitters' surface for a given applied electric field and field enhancement factor over a wide range of parameters. The effects of electron space charge and electric field shielding from neighboring emitters are compared in low current and high current regimes. It is found that the electron space charge is dominant in high current regime, where the Fowler–Nordheim (FN) law becomes the 2D Child–Langmuir (CL) law. The emitter spacing, number of emitters, and emitter's uniformity are also particularly studied, and they are more critical in low current regime. Smooth transition from the FN law to CL law is demonstrated.
Collapse
Affiliation(s)
- W. S. KOH
- School of Electrical and Electronic Engineering, Nanyang Technological University, Singapore, 639798, Singapore
| | - L. K. ANG
- School of Electrical and Electronic Engineering, Nanyang Technological University, Singapore, 639798, Singapore
| |
Collapse
|
18
|
Chen M, Yu F, Hu L, Sun L. Recent progresses on the new condensed forms of single-walled carbon nanotubes and energy-harvesting devices. ACTA ACUST UNITED AC 2011. [DOI: 10.1007/s11434-011-4818-z] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
|
19
|
Wang Y, Fang G, Ma J, Jiang Y. Facial dissociations of water molecules on the outside and inside of armchair single-walled silicon nanotubes: theoretical predictions from multilayer quantum chemical calculations. Theor Chem Acc 2011; 130:463-73. [DOI: 10.1007/s00214-011-1024-7] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/17/2022]
|
20
|
Driscoll JA, Bubin S, French WR, Varga K. Time-dependent density functional study of field emission from nanotubes composed of C, BN, SiC, Si, and GaN. Nanotechnology 2011; 22:285702. [PMID: 21642755 DOI: 10.1088/0957-4484/22/28/285702] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Abstract
Field emission from various types of nanotubes is studied by propagating the electronic density in real space and time using time-dependent density functional theory. Capped (5, 5) C, BN, SiC, Si, and GaN nanotubes are considered. The GaN, SiC, and Si nanotubes were found to be significantly better field emitters than C and BN nanotubes, both in terms of current magnitude and sharpness of peaks in the energy spectra. By analyzing the electronic structure of the various systems it is seen that the nanotubes with the highest currents have electron densities that extend significantly from the nanotube in the emission direction.
Collapse
Affiliation(s)
- Joseph A Driscoll
- Department of Physics and Astronomy, Vanderbilt University, Nashville, TN 37235, USA.
| | | | | | | |
Collapse
|
21
|
Song Y, Usner B, Choi J, Lim SC, Lee YH. Field Emission Properties of Vertically Aligned Carbon Nanotubes Driven by Polar and Non-Polar Gas Adsorption. ACTA ACUST UNITED AC 2011. [DOI: 10.1557/proc-706-z5.8.1] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
AbstractWe studied the gas adsorption effects on the field emission properties of vertically aligned multiwalled carbon nanotube films by exposing them to polar (H2O) and non-polar (N2O) gas molecules. The charge transfer between adsorbates and carbon nanotubes plays an important role in the field emission properties. With bias voltage ~ 1.2V/μm, the field emission properties of the carbon nanotubes are improved by exposing the nitrous oxide while the bias effect with water exposure is less significant. The improvement of the field emission properties by gas exposure is attributed not only to the change in the work function of the carbon nanotubes caused by a charge transfer, but also to the reactivity of the adsorbate gas with localized-cap states.
Collapse
|
22
|
Yu SS, Zheng WT. Effect of N/B doping on the electronic and field emission properties for carbon nanotubes, carbon nanocones, and graphene nanoribbons. Nanoscale 2010; 2:1069-1082. [PMID: 20648331 DOI: 10.1039/c0nr00002g] [Citation(s) in RCA: 55] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/29/2023]
Abstract
Carbon nanotubes, carbon nanocones, and graphene nanoribbons are carbon-based nanomaterials, and their electronic and field emission properties can be altered by either electron donors or electron acceptors. Among both donors and accepters, nitrogen and boron atoms are typical substitutional dopants for carbon materials. The contribution of this paper mainly provides a comprehensive overview of the theoretical topics. The effect of nitrogen/boron doping on the electronic and field emission properties for carbon nanotubes, carbon nanocones, and graphene nanoribbons is reviewed. It is also suggested that nitrogen is more an n-type donor. The discussion about the mechanism of field emission for N-doped carbon nanotubes and electronic structures of N-doped graphene nanoribbons is interesting and timely.
Collapse
Affiliation(s)
- Shan-Sheng Yu
- Department of Materials Science, Laboratory of Automobile Materials, MOE, Jilin University, QianWei Road 2699, Changchun, 130012, P. R. China.
| | | |
Collapse
|
23
|
Wang L, Zhang Y, Zhang Y, Chen X, Lu W. Electronic Structures of S-Doped Capped C-SWNT from First Principles Study. Nanoscale Res Lett 2010; 5:1027-1031. [PMID: 20672070 PMCID: PMC2894202 DOI: 10.1007/s11671-010-9594-1] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/14/2010] [Accepted: 03/29/2010] [Indexed: 05/29/2023]
Abstract
The semiconducting single-walled carbon nanotube (C-SWNT) has been synthesized by S-doping, and they have extensive potential application in electronic devices. We investigated the electronic structures of S-doped capped (5, 5) C-SWNT with different doping position using first principles calculations. It is found that the electronic structures influence strongly on the workfunction without and with external electric field. It is considered that the extended wave functions at the sidewall of the tube favor for the emission properties. With the S-doping into the C-SWNT, the HOMO and LUMO charges distribution is mainly more localized at the sidewall of the tube and the presence of the unsaturated dangling bond, which are believed to enhance workfunction. When external electric field is applied, the coupled states with mixture of localized and extended states are presented at the cap, which provide the lower workfunction. In addition, the wave functions close to the cap have flowed to the cap as coupled states and to the sidewall of the tube mainly as extended states, which results in the larger workfunction. It is concluded that the S-doped C-SWNT is not incentive to be applied in field emitter fabrication. The results are also helpful to understand and interpret the application in other electronic devices.
Collapse
Affiliation(s)
- L Wang
- National Key Laboratory of Nano/Micro Fabrication Technology, Key Laboratory for Thin Film and Microfabrication of the Ministry of Education, Research Institute of Micro/Nanometer Science & Technology, Shanghai Jiao Tong University, 200240, Shanghai, People's Republic of China.
| | | | | | | | | |
Collapse
|
24
|
|
25
|
Riedel D, Cranney M, Martin M, Guillory R, Dujardin G, Dubois M, Sonnet P. Surface-Isomerization Dynamics of trans-Stilbene Molecules Adsorbed on Si(100)-2×1. J Am Chem Soc 2009; 131:5414-23. [DOI: 10.1021/ja807498v] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Damien Riedel
- Laboratoire de Photophysique Moléculaire, CNRS (UPR 3361), Bât. 210, Centre Universitaire de Paris Sud, F91405 ORSAY, France, MINATEC/INPG/IMEP, 3 Parvis Louis Néel, BP 257, F-38016 Grenoble Cedex 1, France, and Institut de Science des Matériaux de Mulhouse (IS2M) LRC CNRS 7228 - Université de Haute Alsace 7014 4, rue des Frères Lumière 68093 Mulhouse Cedex, France
| | - Marion Cranney
- Laboratoire de Photophysique Moléculaire, CNRS (UPR 3361), Bât. 210, Centre Universitaire de Paris Sud, F91405 ORSAY, France, MINATEC/INPG/IMEP, 3 Parvis Louis Néel, BP 257, F-38016 Grenoble Cedex 1, France, and Institut de Science des Matériaux de Mulhouse (IS2M) LRC CNRS 7228 - Université de Haute Alsace 7014 4, rue des Frères Lumière 68093 Mulhouse Cedex, France
| | - Marta Martin
- Laboratoire de Photophysique Moléculaire, CNRS (UPR 3361), Bât. 210, Centre Universitaire de Paris Sud, F91405 ORSAY, France, MINATEC/INPG/IMEP, 3 Parvis Louis Néel, BP 257, F-38016 Grenoble Cedex 1, France, and Institut de Science des Matériaux de Mulhouse (IS2M) LRC CNRS 7228 - Université de Haute Alsace 7014 4, rue des Frères Lumière 68093 Mulhouse Cedex, France
| | - Romain Guillory
- Laboratoire de Photophysique Moléculaire, CNRS (UPR 3361), Bât. 210, Centre Universitaire de Paris Sud, F91405 ORSAY, France, MINATEC/INPG/IMEP, 3 Parvis Louis Néel, BP 257, F-38016 Grenoble Cedex 1, France, and Institut de Science des Matériaux de Mulhouse (IS2M) LRC CNRS 7228 - Université de Haute Alsace 7014 4, rue des Frères Lumière 68093 Mulhouse Cedex, France
| | - Gérald Dujardin
- Laboratoire de Photophysique Moléculaire, CNRS (UPR 3361), Bât. 210, Centre Universitaire de Paris Sud, F91405 ORSAY, France, MINATEC/INPG/IMEP, 3 Parvis Louis Néel, BP 257, F-38016 Grenoble Cedex 1, France, and Institut de Science des Matériaux de Mulhouse (IS2M) LRC CNRS 7228 - Université de Haute Alsace 7014 4, rue des Frères Lumière 68093 Mulhouse Cedex, France
| | - Mathieu Dubois
- Laboratoire de Photophysique Moléculaire, CNRS (UPR 3361), Bât. 210, Centre Universitaire de Paris Sud, F91405 ORSAY, France, MINATEC/INPG/IMEP, 3 Parvis Louis Néel, BP 257, F-38016 Grenoble Cedex 1, France, and Institut de Science des Matériaux de Mulhouse (IS2M) LRC CNRS 7228 - Université de Haute Alsace 7014 4, rue des Frères Lumière 68093 Mulhouse Cedex, France
| | - Philippe Sonnet
- Laboratoire de Photophysique Moléculaire, CNRS (UPR 3361), Bât. 210, Centre Universitaire de Paris Sud, F91405 ORSAY, France, MINATEC/INPG/IMEP, 3 Parvis Louis Néel, BP 257, F-38016 Grenoble Cedex 1, France, and Institut de Science des Matériaux de Mulhouse (IS2M) LRC CNRS 7228 - Université de Haute Alsace 7014 4, rue des Frères Lumière 68093 Mulhouse Cedex, France
| |
Collapse
|
26
|
Zhao JX, Ding YH. The effects of O2 and H2O adsorbates on field-emission properties of an (8, 0) boron nitride nanotube: a density functional theory study. Nanotechnology 2009; 20:085704. [PMID: 19417465 DOI: 10.1088/0957-4484/20/8/085704] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
Abstract
Whether adsorbates might effectively lower the ionization potential (IP) of open-ended boron nitride nanotubes (BNNTs) in order to design BNNTs based on flat-panel display devices is an unanswered question. In the present work, through density functional theory (DFT) calculations we present the first attempt on the effects of O(2) and H(2)O adsorption on the field-emission properties of an open-ended (8, 0) BNNT. The two adsorbates can chemisorb at the tips of the open-ended BNNT with large adsorption energies and significant charge transfer. An applied electric field of 1 eV A(-1) at the tube tip (a) significantly increases the adsorption energy to stabilize the adsorbates, and (b) alters the emission properties such as ionization potential (IP) or bandgap. The IP of the open N-rich-ended BNNT is lowered, thereby making it easier to lose electrons. However, there is a slight increase of the IP for the open B-rich-end BNNT. Our results would be useful not only to better understand the property of open-ended BNNTs, but also to design more efficient field emitters of molecular electronic devices in experiments.
Collapse
Affiliation(s)
- Jing-xiang Zhao
- State Key Laboratory of Theoretical and Computational Chemistry, Institute of Theoretical Chemistry, Jilin University, Changchun 130023, People's Republic of China
| | | |
Collapse
|
27
|
Affiliation(s)
- Daniel Henwood
- a Advanced Technology Institute, University of Surrey , Guildford, UK
| | - J. David Carey
- a Advanced Technology Institute, University of Surrey , Guildford, UK
| |
Collapse
|
28
|
Abstract
The unique and tunable properties of carbon-based nanomaterials enable new technologies for identifying and addressing environmental challenges. This review critically assesses the contributions of carbon-based nanomaterials to a broad range of environmental applications: sorbents, high-flux membranes, depth filters, antimicrobial agents, environmental sensors, renewable energy technologies, and pollution prevention strategies. In linking technological advance back to the physical, chemical, and electronic properties of carbonaceous nanomaterials, this article also outlines future opportunities for nanomaterial application in environmental systems.
Collapse
Affiliation(s)
- Meagan S Mauter
- Department of Chemical Engineering, Environmental Engineering Program, Yale University, P.O. Box 208286, New Haven, Connecticut 06520-8286, USA
| | | |
Collapse
|
29
|
Abstract
Carbon nanobuds (CNBs), a novel carbon nanostructure, have been synthesized recently via covalently bonding C(60) buckyballs to the sidewall of a single-walled carbon nanotube (SWCNT) through cycloaddition reaction [Nasibulin, A. G. et al., Nat. Nanotechnol. 2007, 2, 156]. We perform a first-principles study of structural, electronic, chemical, and field-emission properties of CNBs. It is found that relative stabilities of CNBs depend on the type of carbon-carbon bond dissociated in the cycloaddition reaction. All CNBs are semiconducting regardless of the original SWCNT base being metallic or semiconducting. Chemical attachment of C(60) to SWCNTs can either open up the band gap (e.g., for armchair SWCNT) or introduce impurity states within the band gap, thereby reducing the band gap (for semiconducting SWCNT). In addition, the band gap of CNBs can be modified by changing the density of C(60) attached to the sidewall of the SWCNT. The work function of CNBs can be either slightly higher or lower than that of the parent SWCNT, depending on whether the attached SWCNT is armchair or zigzag. Computed reaction pathway for the formation of CNBs shows that the barriers of both forward and backward reactions are quite high, confirming that CNBs are very stable at room temperature.
Collapse
Affiliation(s)
- Xiaojun Wu
- Department of Chemistry and Nebraska Center for Materials and Nanoscience, University of NebraskaLincoln, Lincoln, Nebraska 68588, USA
| | | |
Collapse
|
30
|
Abstract
We theoretically study the electron transport properties of DNA nucleotides placed in the gap between two single-wall carbon nanotubes capped or terminated with H or N. We show that in the case of C-cap and H-termination the current at low electric bias is dominated by nonresonant tunneling, similarly to the cases of gold electrodes. In nitrogen-terminated nanotube electrodes, the nature of current is primarily quasiresonant tunneling and is increased by several orders of magnitude. We discuss the consequence of our result on the possibility of recognition at the level of single molecule.
Collapse
Affiliation(s)
- Vincent Meunier
- Oak Ridge National Laboratory, P.O. Box 2008, Oak Ridge, Tennessee 37831, USA.
| | | |
Collapse
|
31
|
Zettl A. Chapter 1 Nanotubes: an experimental overview. Carbon Nanotubes: Quantum Cylinders of Graphene. Elsevier; 2008. pp. 1-27. [DOI: 10.1016/s1572-0934(08)00001-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register]
|
32
|
Qiao L, Zheng WT, Xu H, Zhang L, Jiang Q. Field emission properties of N-doped capped single-walled carbon nanotubes: A first-principles density-functional study. J Chem Phys 2007; 126:164702. [PMID: 17477619 DOI: 10.1063/1.2722750] [Citation(s) in RCA: 70] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
The geometrical structures and field emission properties of pristine and N-doped capped (5,5) single-walled carbon nanotubes have been investigated using first-principles density-functional theory. The structures of N-doped carbon nanotubes are stable under field emission conditions. The calculated work function of N-doped carbon nanotube decreases drastically when compared with pristine carbon nanotube, which means the enhancement of field emission properties. The ionization potentials of N-doped carbon nanotubes are also reduced significantly. The authors analyze the field emission mechanism in terms of energy gap between the lowest unoccupied molecular orbital and the highest occupied molecular orbital, Mulliken charge population, and local density of states. Due to the doping of nitrogen atom, the local density of states at the Fermi level increases dramatically and donor states can be observed above the Fermi level. The authors' results suggest that the field emission properties of carbon nanotubes can be enhanced by the doping of nitrogen atom, which are consistent with the experimental results.
Collapse
Affiliation(s)
- L Qiao
- Department of Materials Science, Jilin University, Qian Wei Road 2699, Changchun 130012, People's Republic of China
| | | | | | | | | |
Collapse
|
33
|
Waki S, Hata K, Sato H, Saito Y. Behaviors of single nitrogen molecule on pentagon at carbon nanotube tip observed by field emission microscopy. ACTA ACUST UNITED AC 2007; 25:517. [DOI: 10.1116/1.2429663] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
|
34
|
Meng T, Wang CY, Wang SY. First-principles study of the interactions of Ti and Zr with the tips of open-ended single-wall carbon nanotubes. J Phys Condens Matter 2006; 18:10521-10528. [PMID: 21690934 DOI: 10.1088/0953-8984/18/46/017] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Abstract
Density functional theory is used to study the interactions of Ti and Zr with the tips of open-ended single-wall carbon nanotubes. It is found that Ti or Zr atoms can saturate the dangling bonds of a tip to make it closed. Zr displays much stronger interaction with the contacted carbon atom than Ti. The Fermi energies of the hybrid systems increase dramatically, and the peak values of the density of states near the Fermi levels increase significantly. The field emission properties are discussed qualitatively.
Collapse
Affiliation(s)
- Tiezhu Meng
- Department of Physics, Tsinghua University, Beijing 100084, People's Republic of China
| | | | | |
Collapse
|
35
|
|
36
|
Abstract
We present a systematic study of field-emission performance of prototype boron nitride (BN) nanocones using all-electron density-functional theory method. The effects of apical defects and doping/adsorption on the field emission have been evaluated on the basis of magnitude of ionization potential (IP) and electron affinity (EA). Among BN nanocones examined, two 120 degrees -BN nanocones, namely 120 degrees -4-B-N and 120 degrees -55-mol-B, have been identified as promising candidates for the field-emission electron source. Effects of the applied electric field on the electronic structures of BN nanocones have been investigated. In general, the electronic structures of BN nanocones can be significantly modified by a strong electric field, such as the reduction of the HOMO-LUMO gap and the change in density of states. The interaction between BN nanocones and applied electric field can be described by the second-order Stark effect. In addition, calculations show that the doping/adsorption of an impurity atom results in higher IP or EA values, which is unfavorable to the field emission. Our study suggests that BN nanocones can be considered as alternative cold-emission electron sources.
Collapse
Affiliation(s)
- Wei An
- Department of Chemistry and Nebraska Center for Materials and Nanoscience, University of Nebraska-Lincoln, Lincoln, Nebraska 68588, USA
| | | | | |
Collapse
|
37
|
Abstract
Likely candidates for the global potential energy minima of C60(H2O)n clusters with n < or = 21 are found using basin-hopping global optimization. The potential energy surfaces are constructed using the TIP4P intermolecular potential for the water molecules, a Lennard-Jones water-fullerene potential, and a water-fullerene polarization potential, which depends on the first few nonvanishing C60 multipole polarizabilities. This combination produces a rather hydrophobic water-fullerene interaction. As a consequence, the water component of the lowest C60(H2O)n minima is quite closely related to low-lying minima of the corresponding TIP4P (H2O)n clusters. In most cases, the geometrical substructure of the water molecules in the C60(H2O)n global minimum coincides with that of the corresponding free water cluster. Exceptions occur when the interaction with C60 induces a change in geometry. This qualitative picture does not change significantly if we use the TIP3P model for the water-water interaction. Structures such as C60@(H2O)60, in which the water molecules surround the C60 fullerene, correspond to local minima with much higher potential energies. For such a structure to become the global minimum, the magnitude of the water-fullerene interaction must be increased to an unphysical value.
Collapse
Affiliation(s)
- J Hernández-Rojas
- Departamento de Física Fundamental II, Universidad de La Laguna, 38205 Tenerife, Spain.
| | | | | | | |
Collapse
|
38
|
|
39
|
|
40
|
Affiliation(s)
- Xin Lu
- State Key Laboratory of Physical Chemistry of Solid Surfaces & Center for Theoretical Chemistry, Department of Chemistry, Xiamen University, Xiamen 361005, China.
| | | |
Collapse
|
41
|
Bushuev Y, Davletbaeva S, Muguet F. Hydration Simulations of a Carbon Nanotube, Immersed in Water, according to the 3-Attractor Water Model. Sensors 2005; 5:139-47. [DOI: 10.3390/s5040139] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
|
42
|
WANG YAN, TRUONG THANHN. CORRELATION BETWEEN ELECTRONIC STRUCTURES OF METAL-INTERCALATED SINGLE WALL CARBON NANOTUBES WITH THEIR FIELD EMISSION PROPERTIES. J Theor Comput Chem 2005. [DOI: 10.1142/s0219633605001702] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
The effects of various metal intercalations ( Li , Na and Be ) on the electronic structures and the field emission properties of single-wall carbon nanotubes (SWNT) were investigated using the periodic plane-wave DFT method. We found that intercalations of metal tend to shift the conductive characteristics of the SWNT from those of a semiconductor to those of a quasi-metallic conductor. The Fermi levels for all metal-intercalated in SWNT are moved toward the conduction band, induced by the charge transfer from the metal to the SWNT. Intercalations of Li and Na atoms increase the field emission current, whereas Be intercalation does not affect the field emission current due to the absence of high density of states around the Fermi level. The correlation between the electronic structures for the metal-intercalated nanowires with field emission properties is further discussed in light of the above results.
Collapse
Affiliation(s)
- YAN WANG
- Herry Eyring Center for Theoretical Chemistry, Department of Chemistry, University of Utah, 315 S. 1400 E, Room Dock, Salt Lake City, Utah 84112, USA
| | - THANH N. TRUONG
- Herry Eyring Center for Theoretical Chemistry, Department of Chemistry, University of Utah, 315 S. 1400 E, Room Dock, Salt Lake City, Utah 84112, USA
| |
Collapse
|
43
|
Abstract
Using density functional theory, we have theoretically studied sidewall functionalization of carbon nanotubes (CNT) with a nucleophilic organic carbene, dipyridyl imidazolidene (DPI). When compared to the dissociated system, formation of the adduct from defect-free (5,5) tube and the DPI is weakly exothermic. However, introduction of (5,7,7,5) defect or nitrogen doping at the CNT stabilizes the adduct in both physical and chemical senses, suggesting a possible way to enrich the chemistry of sidewall functionalization. The work function of the adducts is found to decrease by approximately 0.4 eV per DPI/80 atoms. Upon binding of the DPI, electronic structures are modified in such a way that small gaps are introduced, where the size of the gap depends upon the degree of functionalization.
Collapse
Affiliation(s)
- Hong Seok Kang
- College of Natural Science, Jeonju University, Hyoja-dong, Wansan-ku, Chonju, Chonbuk 560-759, Republic of Korea
| |
Collapse
|
44
|
Khazaei M, Farajian AA, Jeong GH, Mizuseki H, Hirata T, Hatakeyama R, Kawazoe Y. Dynamical Criteria for Cs Ion Insertion and Adsorption at Cap and Stem of Carbon Nanotubes: Ab Initio Study and Comparison with Experiment. J Phys Chem B 2004. [DOI: 10.1021/jp0481557] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Mohammad Khazaei
- Institute for Materials Research, Tohoku University, Sendai 980-8577, Japan, and Department of Electronic Engineering, Tohoku University, Sendai 980-8579, Japan
| | - Amir A. Farajian
- Institute for Materials Research, Tohoku University, Sendai 980-8577, Japan, and Department of Electronic Engineering, Tohoku University, Sendai 980-8579, Japan
| | - Goo-Hwan Jeong
- Institute for Materials Research, Tohoku University, Sendai 980-8577, Japan, and Department of Electronic Engineering, Tohoku University, Sendai 980-8579, Japan
| | - Hiroshi Mizuseki
- Institute for Materials Research, Tohoku University, Sendai 980-8577, Japan, and Department of Electronic Engineering, Tohoku University, Sendai 980-8579, Japan
| | - Takamichi Hirata
- Institute for Materials Research, Tohoku University, Sendai 980-8577, Japan, and Department of Electronic Engineering, Tohoku University, Sendai 980-8579, Japan
| | - Rikizo Hatakeyama
- Institute for Materials Research, Tohoku University, Sendai 980-8577, Japan, and Department of Electronic Engineering, Tohoku University, Sendai 980-8579, Japan
| | - Yoshiyuki Kawazoe
- Institute for Materials Research, Tohoku University, Sendai 980-8577, Japan, and Department of Electronic Engineering, Tohoku University, Sendai 980-8579, Japan
| |
Collapse
|
45
|
Abstract
We have investigated adsorption of an O(2) molecule on a double-walled carbon nanotube (DWCNT) edge using density functional theory calculations. An O(2) molecule adsorbs exothermally without an adsorption barrier at open nanotube edges that are energetically favorable with a large adsorption energy of about -9 eV in most cases. Dissociative adsorption of an O(2) molecule induces various spontaneous lip-lip interactions via the bridged carbon atoms, generating the closed tube ends. This explains why the DWCNTs are chemically more stable than the single-walled nanotubes during observed field emission experiments. The field emission takes place via the localized states of the bridged carbon atoms, not via those of the adsorbed oxygen atoms particularly in the armchair nanotubes. We also find that some O(2) precursor states exist as a bridge between tube edges.
Collapse
Affiliation(s)
- Yong Soo Choi
- Department of Physics, Institute of Basic Science, Center for Nanotubes and Nanostructured Composites, Sungkyunkwan University, Suwon 440-746, Korea
| | | | | | | |
Collapse
|
46
|
Zhao M, Xia Y, Lewis JP, Mei L. Chemical Reactivity of Single-Walled Carbon Nanotubes to Amidogen from Density Functional Calculations. J Phys Chem B 2004. [DOI: 10.1021/jp037055i] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Mingwen Zhao
- Department of Physics, Shandong University, Jinan 250100, China, and Department of Physics and Astronomy, Brigham Young University, Provo, Utah 84602-4658
| | - Yueyuan Xia
- Department of Physics, Shandong University, Jinan 250100, China, and Department of Physics and Astronomy, Brigham Young University, Provo, Utah 84602-4658
| | - James P. Lewis
- Department of Physics, Shandong University, Jinan 250100, China, and Department of Physics and Astronomy, Brigham Young University, Provo, Utah 84602-4658
| | - Liangmo Mei
- Department of Physics, Shandong University, Jinan 250100, China, and Department of Physics and Astronomy, Brigham Young University, Provo, Utah 84602-4658
| |
Collapse
|
47
|
Abstract
Single-walled carbon nanotubes have been reacted with osmium tetroxide (OsO(4)) in solution in the presence of O(2) and UV irradiation at 254 nm. We observe one main structural motif, namely thickly coated nanotube structures, densely covered with OsO(2), consisting of multiple bundles of derivatized tubes. In a few instances, bridging uncoated tubes, connecting these thickly coated structures, incorporate a number of smaller nanotube bundles, projecting out from the larger functionalized aggregates of tubes. It is believed that OsO(2) (a) initially forms on the nanotubes by the preferential covalent sidewall functionalization of metallic nanotubes and (b) subsequently self-aggregates. The formation of an intermediate charge-transfer complex is likely the basis for the observed selectivity and reactivity of metallic tubes. Extensive characterization of these osmylated adducts has been performed using a variety of electron microscopy and optical spectroscopy techniques.
Collapse
Affiliation(s)
- Sarbajit Banerjee
- Department of Chemistry; State University of New York at Stony Brook; Stony Brook, New York 11794-3400, USA
| | | |
Collapse
|
48
|
Kim C, Choi YS, Lee SM, Park JT, Kim B, Lee YH. The effect of gas adsorption on the field emission mechanism of carbon nanotubes. J Am Chem Soc 2002; 124:9906-11. [PMID: 12175252 DOI: 10.1021/ja026538h] [Citation(s) in RCA: 41] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
We have investigated systematically the effects of various gas adsorbates (H2, N2, O2, and H2O) on the electronic structures and the field emission properties of open edges of single-walled carbon nanotubes by density functional calculations. All of the molecules, except N2, dissociate and chemisorb on open nanotube edges with large adsorption energies. The Fermi levels are moved toward the valence (conduction) bands for O2 (H2, H2O) adsorption induced by the Mulliken charge transfer on the tube edge. The Fermi level shift for N2 adsorption is negligible. Adsorption of H2O enhances the field emission current, whereas H2 adsorption does not affect the field emission current much because of the absence of the density of states near the Fermi level. The correlation of the electronic structures and the field emission current is further discussed.
Collapse
Affiliation(s)
- Changwook Kim
- Department of Chemistry, Korea Advanced Institute of Science and Technology, Daejeon 305-701, Korea
| | | | | | | | | | | |
Collapse
|