(420u) In Situ XPS Study of the Influence of Water Vapor On Catalytic Decomposition of Ethylene During Carbon Nanotube Growth

Water-assisted chemical vapor deposition (CVD) has become one of the leading methods for producing vertically aligned carpets of single-walled carbon nanotube (SWNT) due to its high catalytic efficiency. The mechanism for the dissociative adsorption of the hydrocarbon on catalyst surfaces in the presence of water vapor is still not fully understood. In this work, we present critical evidence from in situ X-ray photoelectron spectroscopy (XPS) and Auger electron spectroscopy (AES) experiments using ethylene decomposition over Fe catalyst that further rationalizes the growth enhancement observed during water-assisted CVD growth of nanotubes.