Photoemission studies of gold clusters thermally evaporated on multiwall carbon nanotubes

Thereafter, the interaction between evaporated gold and pristine or oxygen-plasma-treated MWCNTs is investigated. Gold is found to nucleate at defect sites, whether initially present or introduced by oxygen plasma treatment. Gold cluster uniform dispersion is observed on plasma-treated CNTs. The absence of additional features in the Au 4f and C 1s core levels spectra testifies that no Au-C bond is formed. The Au 4f core level energy shift towards high binding energy for the smallest clusters indicates cluster charging during the photoionization process, suggesting poor electrical contact between gold clusters and CNT surface. Cluster size effects are observed on the valence band spectra.