標題: On the use of new oxidized Co-Cr-Pt-O catalysts for vertically-aligned few-walled carbon nanotube forest synthesis in electron cyclotron resonance chemical vapor deposition
作者: Teng, I-Ju
Huang, Chong-Sian
Hsu, Hui-Lin
Chung, I-Chuan
Jian, Sheng-Rui
Kherani, Nazir P.
Kuo, Cheng-Tzu
Juang, Jenh-Yih
材料科學與工程學系
電子物理學系
奈米科技中心
Department of Materials Science and Engineering
Department of Electrophysics
Center for Nanoscience and Technology
公開日期: 1-十二月-2014
摘要: A new class of the multi-element catalysis system, Co-Cr-Pt-O, is used for vertically-aligned few-walled carbon nanotube (CNT) forest synthesis by a sandwich-growth technology in electron cyclotron resonance chemical vapor deposition. The effect of catalyst compositions on the resulting particle sizes after pretreatment, and the influence of process parameters on the CNT forest heights and diameters are investigated. Results show that a plasma pretreatment step reduces the metal oxides present in the as-deposited Co-Cr-Pt-O catalyst to their metallic states or to mixed metallic/oxidic states, and the co-catalytic synergistic effect during the reduction process thus leads to the production of uniformly small particles with a size of 3.3-3.9 nm over the substrate. Moreover, with CH4 as the carbon source, vertically-aligned CNT forests of similar to 12 mu m in height are achieved, and further characterizations indicate that the forests consist of dominant triple-walled nanotubes with an average inner tube diameter of 3.2-3.7 nm mostly. Additionally, field emission measurements show that the turn-on field of the CNT-forest emitters is below 2.6 V/mu m, and the emission current density can reach 110 mA/cm(2) at 4.5 V/mu m. High reproducibility of field emission characteristics and Raman signals suggests the regularity of the CNT forests in structure and size. (C) 2014 Elsevier Ltd. All rights reserved.
URI: http://dx.doi.org/10.1016/j.carbon.2014.09.040
http://hdl.handle.net/11536/123887
ISSN: 0008-6223
DOI: 10.1016/j.carbon.2014.09.040
期刊: CARBON
Volume: 80
起始頁: 808
結束頁: 822
顯示於類別:期刊論文


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