Engineering Low-Aspect Ratio Carbon Nanostructures: Nanocups, Nanorings, and Nanocontainers

Chun, Hyonho; Hahm, Myung Gwan; Homma, Yoshikazu; Meritz, Rebecca; Kuramochi, K.; Menon, Latika; Ci, Lijie; Ajayan, Pulickel M.; Jung, Yung Joon

doi:10.1021/nn9001903

Cited by 50 publications

(56 citation statements)

References 32 publications

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“…[1][2][3] Conductivity, resistance of emitter/substrate interfaces, surface work function of material and emitter tip quality are some of the important factors which determine the efficiency of field-emission. 2,4 For field emission display applications, it is necessary to grow vertically aligned carbon nanotube (CNT) arrays on a large scale with suitable emitter density and high aspect ratio.…”

Section: Introductionmentioning

confidence: 99%

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High-performance field emission device utilizing vertically aligned carbon nanotubes-based pillar architectures

et al. 2018

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The vertical aligned carbon nanotubes (CNTs)-based pillar architectures were created on laminated silicon oxide/silicon (SiO2/Si) wafer substrate at 775 °C by using water-assisted chemical vapor deposition under low pressure process condition. The lamination was carried out by aluminum (Al, 10.0 nm thickness) as a barrier layer and iron (Fe, 1.5 nm thickness) as a catalyst precursor layer sequentially on a silicon wafer substrate. Scanning electron microscope (SEM) images show that synthesized CNTs are vertically aligned and uniformly distributed with a high density. The CNTs have approximately 2–30 walls with an inner diameter of 3–8 nm. Raman spectrum analysis shows G-band at 1580 cm−1 and D-band at 1340 cm−1. The G-band is higher than D-band, which indicates that CNTs are highly graphitized. The field emission analysis of the CNTs revealed high field emission current density (4mA/cm2 at 1.2V/μm), low turn-on field (0.6 V/μm) and field enhancement factor (6917) with better stability and longer lifetime. Emitter morphology resulting in improved promising field emission performances, which is a crucial factor for the fabrication of pillared shaped vertical aligned CNTs bundles as practical electron sources.

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Section: Introductionmentioning

confidence: 99%

“…The CNTs have approximately 2-30 walls with an inner diameter of 3-8 nm. Raman spectrum analysis shows G-band at 1580 cm 1 and D-band at 1340 cm 1 . The G-band is higher than D-band, which indicates that CNTs are highly graphitized.…”

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confidence: 96%

High-performance field emission device utilizing vertically aligned carbon nanotubes-based pillar architectures

et al. 2018

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“…The outer diameter and wall thickness of the CNTs are estimated to be 90 and 6 nm, respectively. Therefore, etching AAO films before CNTs growth can cause remarkable increase of the CNTs outer diameter but negligible thickening of the CNT wall.Because of the copying effect of the template-synthesized CNTs on the size and morphology of pores of the AAO template, [9][10][11][12] the outer diameter and the length of the CNTs obtained in our experiment can be taken as pore diameter and pore depth of the AAO film, respectively (Fig. 1e).…”

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confidence: 99%

Color Fine‐Tuning of CNTs@AAO Composite Thin Films via Isotropically Etching Porous AAO Before CNT Growth and Color Modification by Water Infusion

Zhao

Meng

et al. 2010

Advanced Materials

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Optical interference structures exist in nature, e.g., in feathers of birds and wings of insects, and exhibit vivid colors, which originate from the mechanism of optical interference and thus can vary notably with the viewing-angle and the refractive index of the dielectric medium surrounding the optical interference structures. [1][2][3] Because of the attractive applications of optical interference structures in color display, decoration, anti-counterfeiting and liquid sensors, considerable attention has been paid to the construction of man-made systems with interference colors, such as multilayer structures, [4] silicon dimple arrays, [5] and anodic aluminum oxide (AAO) thin films embedded with metal. [6,7] Recently, it has been reported that AAO thin films embedded with carbon nanotubes (CNTs) (denoted as CNTs@AAO composite thin films) display brilliant colors, which stem from the interference between the reflected light from the AAO top planar surface and the emergent light reflected on the AAO-Al interface.[8] As colors of the CNTs@AAO composite thin films are mainly determined by the interference band with the maximum reflectance (B max ) in the visible region, and B max shifts by changing the AAO film thickness, color tuning of the CNTs@AAO composite thin films can be attained by varying the AAO film thickness in the anodization. However, B max is very sensitive to the thickness of the AAO film, and the pore growth rate of the AAO in the anodization is very fast, so it would be difficult for this approach to tune the color of the CNTs@AAO composite thin film in a well-controlled manner. In addition, the as-prepared CNTs@AAO composite thin films are hydrophobic and thus prohibit water infusion.[9] If the CNTs@AAO composite thin films can be changed into hydrophilic, the composite thin films might be used as water sensors. Here, by applying wetchemical etching to porous AAO thin films to thin the AAO films and widen the AAO pores isotropically before CNTs growth, controllable precise color tuning of the CNTs@AAO composite thin films has been achieved. Moreover, via further plasma cleaning, the CNTs@AAO composite thin films with large AAO pore diameter can change their colors remarkably after water infusion. Additionally, via applying wet-chemical etching to different areas of one piece of AAO film for rationally different durations, patterned CNTs@AAO composite thin film with each area showing a unique color has been obtained. The details of the fabrication of the AAO, the etching of the AAO, and the growth of the CNTs are given in the Experimental section. Figure 1a and b are SEM images of the CNTs released from the CNTs@AAO composite thin films. Figure 1a shows free-standing CNTs aggregating into clumps and formed inside the pores of the AAO films without being etched. Figure 1b Figure 1d is the TEM image of the CNTs from Figure 1b. The outer diameter and wall thickness of the CNTs are estimated to be 90 and 6 nm, respectively. Therefore, etching AAO films before CNTs growth can cause remarkable increase ...

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“…(B) Applications of the doped carbon nanomaterials [13][14][15][16][17][18][19][20]. The common carbon reported shapes: (A) graphene sheet [1], (B) fullerenes [2], (C) carbon nanospheres [3], (D) nanocups [4], (E) bamboo-like CNTs [5], (F) nanorods [6]. (A) Reprinted (adapted) with permission from Ref.…”

Section: Figure 2 (A)mentioning

confidence: 99%

“…Substantial research on their properties and potential applications has since ensued. Among them, the study of the shaped carbon nanomaterials (Figure 1) [1][2][3][4][5][6] such as the carbon nanotubes (CNTs), have stimulated enormous interest for constructing the sensors due to their unique physical and chemical properties, such as high surface-to-volume ratio, high conductivity, high strength, and chemical inertness. The CNTs are rolled up cylinders of graphene sheets.…”

Section: Introductionmentioning

confidence: 99%

Synthesis and electrochemical applications of nitrogen-doped carbon nanomaterials

Majeed¹,

Zhao²,

Zhang³

et al. 2013

Nanotechnology Reviews

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Abstract:Nitrogen doping is an effective way to tailor the properties of the shaped carbon materials, including the nanotubes, nanocups, nanofibers, as well as the nanorods, and render their potential use for various applications. The common bonding configurations obtained on the N insertion is the pyridinic N and pyrrolic N, which impart the characteristic properties to these carbon materials. This review will focus on the nitrogen-doped carbon materials, the doping effect on the electrochemistry of the doped nanomaterials, and the various synthetic methods to introduce N into the carbon network. The potential applications of the N-doped materials are also reviewed on the basis of the experimental and theoretical studies in electrochemistry.

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Engineering Low-Aspect Ratio Carbon Nanostructures: Nanocups, Nanorings, and Nanocontainers

Cited by 50 publications

References 32 publications

High-performance field emission device utilizing vertically aligned carbon nanotubes-based pillar architectures

High-performance field emission device utilizing vertically aligned carbon nanotubes-based pillar architectures

Color Fine‐Tuning of CNTs@AAO Composite Thin Films via Isotropically Etching Porous AAO Before CNT Growth and Color Modification by Water Infusion

Synthesis and electrochemical applications of nitrogen-doped carbon nanomaterials

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