• 제목, 요약, 키워드: carbon nanowires

검색결과 50건 처리시간 0.04초

Pd/SPK 촉매상에서 메탄의 열분해 반응으로부터 탄소 나노튜브 및 탄소 나노선의 제조 (Preparation of Carbon Nanotubes and Carbon Nanowires from Methane Pyrolysis over Pd/SPK Catalyst)

  • 서호준;권오윤
    • 공업화학
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    • v.18 no.1
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    • pp.94-97
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    • 2007
  • 대기압 조건에서 고정층 상압 유통식 반응기를 사용하여 Pd(5)/SPK 촉매상에서 산소의 몰 비 변화에 따른 메탄의 열분해 반응으로부터 탄소 나노튜브 및 탄소 나노선을 제조하였으며, SEM과 TEM을 이용하여 분석하였다. $CH_4/O_2$의 몰 비가 1인 경우, 촉매층 지지대 표면상에 탄소가 거의 침적되지 않았으나, $CH_4/O_2$의 몰 비가 2인 경우에는 촉매층 지지대 표면상에 반응기를 봉쇄할 정도로 다량의 탄소가 침적되었다. 침적된 탄소를 SEM과 TEM을 통하여 분석한 결과 많은 수의 단일 벽 탄소 나노튜브와 탄소 나노선들이 만들어졌음을 확인할 수 있었다. 촉매 표면상에 침적된 탄소 나노튜브의 생성 메카니즘은 첨단성장방식이었고, 촉매 지지대 표면상에 만들어진 탄소 나노튜브 및 나노선들의 생성은 일정한 탄소 성장속도 벡터와 탄소 나노선의 링구조의 핵형성이 중요한 역할을 하였다. SPK 촉매 담체는 열 안정성이 우수하였으며, $N_2$ 흡착등온선은 중기공 세공이 잘 발달된 IV형이었다.

Nanotechnologies in Displays : TFTs with Carbon Nanotubes and Semiconductor Nanowires.

  • Pribat, Didier;Cojocaru, Costel;Gowtham, M.;Eude, L.;Balan, A.;Bondavalli, P.;Legagneux, P.
    • 한국정보디스플레이학회:학술대회논문집
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    • pp.1245-1248
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    • 2007
  • We propose new approaches to thin film transistor fabrication that use carbon nanotubes and semiconductor nanowires as active elements. These nanomaterials which are essentially studied in the context of the post CMOS era will certainly impact the active matrix display industry in the near future.

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Synthesis of Vertically Aligned SiNW/Carbon Core-shell Nanostructures

  • 김준희;김민수;김동환
    • 한국진공학회:학술대회논문집
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    • pp.488.2-488.2
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    • 2014
  • Carbon-based materials such as carbon nanotubes and graphene have emerged as promising building blocks in applications for nanoelectronics and energy devices due to electrical property, ease of processability, and relatively inert electrochemistry. In recent years, there has been considerable interest in core-shell nanomaterials, in which inorganic nanowires are surrounded by inorganic or organic layers. Especially, carbon encapsulated semiconductor nanowires have been actively investigated by researchers in lithium ion batteries. We report a method to synthesize silicon nanowire (SiNW) core/carbon shell structures by chemical vapor deposition (CVD), using methane (CH4) as a precursor at growth temperature of $1000{\sim}1100^{\circ}C$. Unlike carbon-based materials synthesized via conventional routes, this method is of advantage of metal-catalyst free growth. We characterized these materials with FE-SEM, FE-TEM, and Raman spectroscopy. This would allow us to use these materials for applications ranging from optoelectronics to energy devices such as solar cells and lithium ion batteries.

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탄소나노튜브 속에 성장된 구리 나노와이어의 구조 (Structures of Ultrathin Copper Nanowires Encapsulated in Carbon Nanotubes)

  • 최원영;강정원;송기오;황호정
    • 한국전기전자재료학회:학술대회논문집
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    • pp.294-299
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    • 2003
  • We have investigated the structures of copper nanowires encapsulated in carbon nanotubes using a structural optimization process applied to the steepest descent method. The results showed that the stable morphology of the cylindrical ultrathin copper nanowires in carbon nanotubes is multishell packs consisted of coaxial cylindrical shells. As the diameter of copper nanotubes increased, the encapsulated copper nanowires have the face centered cubic structure as the bulk. Both the semiclassical orbits in a circle and the circular rolling of a triangular network can explain the structures of ultrathin multishell copper nanowires encapsulated in carbon nanotubes.

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Hydrogen sensing of Nano thin film and Nanowire structured cupric oxide deposited on SWNTs substrate: A comparison

  • ;;오동훈;;정혁;김도진
    • 한국재료학회:학술대회논문집
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    • pp.52.1-52.1
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    • 2009
  • Cupric oxide (CuO) is a p-type semiconductor with band gap of ~1.7 eV and reported to be suitable for catalysis, lithium-copper oxide electrochemical cells, and gas sensors applications. The nanoparticles, plates and nanowires of CuO were found sensing to NO2, H2S and CO. In this work, we report about the comparison about hydrogen sensing of nano thin film and nanowires structured CuO deposited on single-walled carbon nanotubes (SWNTs). The thin film and nanowires are synthesized by deposition of Cu on different substrate followed by oxidation process. Nano thin films of CuO are deposited on thermally oxidized silicon substrate, whereas nanowires are synthesized by using a porous thin film of SWNTs as substrate. The hydrogen sensing properties of synthesized materials are investigated. The results showed that nanowires cupric oxide deposited on SWNTs showed higher sensitivity to hydrogen than those of nano thin film CuO did.

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탄소나노튜브와 은나노와이어 복합 유연투명전극 필름 기술 (Nanocarbon/silver Nanowire Hybrid Flexible Transparent Conducting Film Technology)

  • 한중탁
    • 한국표면공학회지
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    • v.49 no.4
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    • pp.323-330
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    • 2016
  • The flexible transparent conducting films (TCFs) are required to realize flexible optoelectronic devices. 1D nanomaterials such as carbon nanotubes (CNTs), metal nanowires are good candidates to replace indium tin oxide that is currently used to fabricate transparent electrode. Particularly, silver nanowires are used to produce flexible TCFs. In this review, we introduce TCF technologies based on silver nanowires/CNTs hybrid structures. CNTs can compromise drawbacks of silver nanowires for applications in high performance TCFs for optoelectronic devices.

Highly Porous Tungsten Oxide Nanowires As Resistive Sensor for Reducing Gases

  • Nguyen, Minh Vuong;Hoang, Nhat Hieu;Jang, Dong-Mi;Jung, Hyuck;Kim, Do-Jin
    • 한국재료학회:학술대회논문집
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    • pp.16.1-16.1
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    • 2011
  • Gas sensor properties of $WO_3$ nanowire structures have been studied. The sensing layer was prepared by deposition of tungsten metal on porous single wall carbon nanotubes followed by thermal oxidation. The morphology and crystalline quality of $WO_3$ material was investigated by SEM, TEM, XRD and Raman analysis. A highly porous $WO_3$ nanowire structure with a mean diameter of 82 nm was obtained. Response to CO, $NH_3$ and $H_2$ gases diluted in air were investigated in the temperature range of $100{\sim}340^{\circ}C$ The sensor exhibited low response to CO gas and quite high response to $NH_3$ and $H_2$ gases. The highest sensitivity was observed at $250^{\circ}C$ for $NH_3$ and $300^{\circ}C$ for $H_2$. The effect of the diameters of $WO_3$ nanowires on the sensor performance was also studied. The $WO_3$ nanowires sensor with diameter of 40 nm showed quite high sensitivity, fast response and recovery times to $H_2$ diluted in dry air. The sensitivity as a function of detecting gas concentrations and gas sensing mechanism was discussed. The effect of dilution carrier gases, dry air and nitrogen, was examined.

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Semiconductor Nanowires;Their Emission Stability and Energy Distribution

  • Yu, Se-Gi;Yi, Whi-Kun;Lee, Sang-Hyun;Heo, Jung-Na;Jeong, Tae-Won;Lee, Jeong-Hee;Lee, Soo-Chang;Kim, J.M.;Lee, Cheol-Jin;Lyu, Seung-Chul;Han, Jae-Hee;Yoo, Ji-Beom
    • 한국정보디스플레이학회:학술대회논문집
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    • pp.1028-1031
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    • 2002
  • Ga-based semiconductor nanowires (GaN, GaP) were synthesized by the reaction of Ga metal and GaN/GaP powder with a $NH_3/Ar$ gas using thermal chemical vapor deposition. The field emission and emission stability under oxygen and argon environments were investigated. Field emission energy distributions of electrons from these nanowires revealed that field emission mechanism of the semiconductor nanowires were different from carbon nanotubes.

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Synthesis of SnO2 nanowires on one-dimensional carbonization cotton fabric

  • Khai, Tran Van;Shim, Kwang-Bo
    • 한국결정성장학회지
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    • v.22 no.1
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    • pp.25-28
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    • 2012
  • Tin-oxide ($SnO_2$) nanowires have been synthesized on one-dimensional (1D) carbonization cotton fabric using chemical vapour deposition method. One-dimensional (1D) carbonization cotton fabric has been synthesized from cotton fabric using annealing process in nitrogen gas at $1000^{\circ}C$. The $SnO_2$ nanowires are single-crystalline rutile structures with 20 nm in diameter and 10 ${\mu}m$ in length. Scanning electron microscopy (SEM), x-ray photoelectron spectroscopy, Raman spectroscopy, transmission electron microscopy and photoluminescence (PL) spectroscopy were utilized to characterize the as-synthesized products.

Characteristics of Silicon Carbide Nanowires Synthesized on Porous Body by Carbothermal Reduction

  • Kim, Jung-Hun;Choi, Sung-Churl
    • 한국세라믹학회지
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    • v.55 no.3
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    • pp.285-289
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    • 2018
  • We synthesized silicon carbide (${\beta}-SiC$) nanowires with nano-scale diameter (30 - 400 nm) and micro-scale length ($50-200{\mu}m$) on a porous body using low-grade silica and carbon black powder by carbothermal reduction at $1300-1600^{\circ}C$. The SiC nanowires were formed by vapor-liquid-solid deposition with self-evaporated Fe catalysts in low-grade silica. We investigated the characteristics of the SiC nanowires, which were grown on a porous body with Ar flowing in a vacuum furnace. Their structural, optical, and electrical properties were analyzed with X-ray diffraction (XRD), transmission electron microscopy (TEM), and selective area electron diffraction (SAED). We obtained high-quality SiC single crystalline nanowire without stacking faults that may have uses in industrial applications.