In this study, modified catalytic chemical vapor deposition (CCVD) method was applied to control the CNTs (carbon nanotubes) growth. Since titanium (Ti) substrate and iron (Fe) catalysts react one another and form a new phase (Fe₂TiO₅) above 700°C, the decrease of CNT yield above 800°C where methane gas decomposes is inevitable under common CCVD method. Therefore, we synthesized CNTs on the Ti substrate by dividing the tube furnace into two sections (left and right) and heating them to different temperatures each. The reactant gas flew through from the end of the right tube furnace while the Ti substrate was placed in the center of the left tube furnace. When the CNT growth temperature was set 700/950°C (left/right), CNTs with high yield were observed. Also, by examining the micro-structure of CNTs of 700/950°C, it was confirmed that CNTs show the bamboo-like structure.

Citations

Citations to this article as recorded by  

• Fabrication of Ti Porous body with Improved Specific Surface Area by Synthesis of CNTs
  Hye Rim Choi, Jong Min Byun, Myung-Jin Suk, Sung-Tag Oh, Young Do Kim
  Journal of Korean Powder Metallurgy Institute.2016; 23(3): 235.     CrossRef
• Synthesis of CNT on a Camphene Impregnated Titanium Porous Body by Thermal Chemical Vapor Deposition
  Hogyu Kim, Hye Rim Choi, Jong Min Byun, Myung-Jin Suk, Sung-Tag Oh, Young Do Kim
  Journal of Korean Powder Metallurgy Institute.2015; 22(2): 122.     CrossRef

This paper describes the surface modification effect of a Ti substrate for improved dispersibility of the catalytic metal. Etching of a pure titanium substrate was conducted in 50% H₂SO₄, 50°C for 1 h-12 h to observe the surface roughness as a function of the etching time. At 1 h, the grain boundaries were obvious and the crystal grains were distinguishable. The grain surface showed micro-porosities owing to the formation of micro-pits less than 1 μm in diameter. The depths of the grain boundary and micro-pits appear to increase with etching time. After synthesizing the catalytic metal and growing the carbon nano tube (CNT) on Ti substrate with varying surface roughness, the distribution trends of the catalytic metal and grown CNT on Ti substrate are discussed from a micro-structural perspective.

Citations

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• Solvent induced surface modifications on hydrogen storage performance of ZnO nanoparticle decorated MWCNTs
  Madhavi Konni, Anima S. Dadhich, Saratchandra Babu Mukkamala
  Sustainable Energy & Fuels.2018; 2(2): 466.     CrossRef
• Influence of nickel nanoparticles on hydrogen storage behaviors of MWCNTs
  Ye-Ji Han, Soo-Jin Park
  Applied Surface Science.2017; 415: 85.     CrossRef
• Spontaneous Formation of Titanium Nitride on the Surface of a Ti Rod Induced by Electro-Discharge-Heat-Treatment in an N2 Atmosphere
  W.H. Lee, Y.H. Yoon, Y.H. Kim, Y.K. Lee, J.Y. Kim, S.Y. Chang
  Archives of Metallurgy and Materials.2017; 62(2): 1281.     CrossRef
• Synthesis of CNT on a Camphene Impregnated Titanium Porous Body by Thermal Chemical Vapor Deposition
  Hogyu Kim, Hye Rim Choi, Jong Min Byun, Myung-Jin Suk, Sung-Tag Oh, Young Do Kim
  Journal of Korean Powder Metallurgy Institute.2015; 22(2): 122.     CrossRef