Adsorption Dynamics of Alkanes on Single-Wall Carbon Nanotubes: A Molecular Beam Scattering Study

Abstract

The adsorption dynamics of n-/isobutane on “closed”-end (as-prepared, c-CNTs) and open-end (vacuum-annealed) carbon nanotubes (o-CNTs) have been studied by molecular beam scattering adsorption probability measurements. Thermal desorption spectroscopy (TDS) and scanning electron microscopy have been used to characterize the CNTs. Evident from TDS data, o-CNTs allow internal adsorption sites to be populated, which is correlated with an increase in the initial adsorption probabilities as compared with c-CNTs, consistent with the enhancement in the surface area by opening the tube ends. Furthermore, precursor-mediated adsorption dynamics were observed.