Carbon Nanotube-Polypyrrole Composite Electrode Materials Produced In Situ by Electron Bombardment in Radio-Frequency Plasma Afterglows

摘要

Free electrons, produced in radio-frequency (13.56MHz) glow discharges of O-2, N-2, and Ar, are recruited to multi-walled carbon nanotubes (MWNTs) by a positive electric field. Electron bombardment degradation is restricted to the tips of the MWNTs. SEM images show that a surface deposited layer develops during degradation. Gas phase plasma reactions form polycyclic aromatic hydrocarbons and plasma polymers, which are re-deposited on the MWNTs as thin films. The plasma polymer is identified as a polypyrrole (PPy)-like plasma polymer, as shown by molecular optical absorption spectroscopy and GC-MS. FT-IR spectra confirm that the surface films are composed of the same plasma polymer. Inert gas plasmas produce higher-molecular weight plasma polymers, while O-2 plasma treatments produce over-oxidized polypyrrolic-plasma polymer films.