Cobalt ultrathin film catalyzed ethanol chemical vapor deposition of single-walled carbon nanotubes
Cobalt ultrathin film catalyzed ethanol chemical vapor deposition of single-walled carbon nanotubes
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DOI：
10.1021/jp060693r
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发表时间：
2006-06-15
影响因子：
3.3
通讯作者：
O'Brien, Stephen
中科院分区：
文献类型：
--
作者：
Huang, Limin;White, Brian;O'Brien, Stephen
我们报道了一种简单有效的化学气相沉积（CVD）工艺，该工艺可以使用钴纳米薄膜（类似于1 nm）作为催化剂和乙醇作为碳原料生长定向和长的单壁碳纳米管（SWNTs）。在这个过程中，毫米到厘米长，定向和高质量的单壁碳纳米管可以在各种平坦的衬底表面上水平生长，穿过数百微米宽的狭缝，或在高达20 μ m的垂直屏障上生长。这样的观察表明，在生长期间，碳纳米管悬浮在气流中。乙醇中的痕量自含水（0.2- 5wt%）可充当温和氧化剂以清洁纳米管并延长催化剂的寿命，但在850 ℃的CVD温度下未观察到产率提高。我们发现，倾斜的衬底支持钴薄膜催化剂可以生长更多，更长的碳纳米管。长单壁碳纳米管的生长机制进行了讨论。
We report a simple and efficient chemical vapor deposition (CVD) process that can grow oriented and long single-walled carbon nanotubes (SWNTs) using a cobalt ultrathin film (similar to 1 nm) as the catalyst and ethanol as carbon feedstock. In the process, millimeter- to centimeter-long, oriented and high-quality SWNTs can grow horizontally on various flat substrate surfaces, traverse slits as large as hundreds of micrometers wide, or grow over vertical barriers as high as 20 mu m. Such observations demonstrate that the carbon nanotubes are suspended in the gas flow during the growth. The trace amount of self-contained water (0.2-5 wt %) in ethanol may act as a mild oxidizer to clean the nanotubes and to elongate the lifetime of the catalysts, but no yield improvement was observed at the CVD temperature of 850 degrees C. We found that tilting the substrates supporting the Co ultrathin film catalysts can grow more, longer carbon nanotubes. A mechanism is discussed for the growth of long SWNTs.