2012.11.22

Dr. Placidus B. Amama
      Research Scientist,
      University of Dayton Research Institute (UDRI) &
      Air Force Research Laboratory (AFRL) Dayton, Ohio, USA

Title：Rational Catalyst Design for Enhanced and Controlled Growth of Carbon Nanotube Carpets via Chemical Vapor Deposition

Summary：
There has been growing interest in densely packed, vertically aligned single-walled carbon nanotube (SWCNT) carpets because of their suitability in a growing number of important technological applications. Among the existing methods for the growth of SWCNT carpets, catalytic chemical vapor deposition (CVD) appears to be the most suitable. Using an alumina/Fe catalyst and a suitable carbon feedstock, SWCNT carpets of millimeter-scale heights can be grown via water-assisted CVD. However, for efficient and controlled growth of SWCNT carpets to be achieved, there are several challenges that need to be addressed, such as unexpected or early growth termination of carpets that limits yield, difficulty in performing carpet growth on metallic or non-alumina supporting layers, and the lack of proper understanding of the growth mechanisms of carpets including many important aspects of supportmetal interactions. In my talk, I will discuss the secret role of water during carpet growth and show how the growth termination process can be explained on the basis of Ostwald ripening and subsurface diffusion of the catalyst. Further, I will discuss the relationship between the 3D evolution of Fe catalyst supported on different alumina types and the catalyst behavior (activity and lifetime). Finally, new strategies for improving the activity and lifetime of Fe catalysts during carpet growth will be discussed.

Schedule：15:30-17:00 November 22, 2012 (Thursday)
Place：Room 232, 3th floor, Engineering Bld #2, Hongo Campus

Attached file： The 124th open seminar.pdf