We combine in situ X-ray photoelectron spectroscopy and ex situ electron and Raman spectroscopy to study chemical interactions of SiO2-supported Fe catalyst films during C2H2 exposure in the 400-600 degrees C temperature range. Carbon nanotubes nucleate at C,H, pressures below 10(-6) mbar, which allows a time-resolved recording of core level spectra. We find a rapid transition from an initial chemisorbed carbon on metallic Fe catalyst nanoparticles to a sp(2) graphitic carbon network. Pre-treating the Fe catalyst film by H-2 sputtering influences the initial catalyst de-wetting and increases carbon nanotube yield. (C) 2007 Elsevier B.V. All rights reserved.
Surface-bound chemical vapour deposition of carbon nanotubes: In situ study of catalyst activation
Cepek C
2008
Abstract
We combine in situ X-ray photoelectron spectroscopy and ex situ electron and Raman spectroscopy to study chemical interactions of SiO2-supported Fe catalyst films during C2H2 exposure in the 400-600 degrees C temperature range. Carbon nanotubes nucleate at C,H, pressures below 10(-6) mbar, which allows a time-resolved recording of core level spectra. We find a rapid transition from an initial chemisorbed carbon on metallic Fe catalyst nanoparticles to a sp(2) graphitic carbon network. Pre-treating the Fe catalyst film by H-2 sputtering influences the initial catalyst de-wetting and increases carbon nanotube yield. (C) 2007 Elsevier B.V. All rights reserved.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
