XPS and NEXAFS characterisation of plasma deposited vertically aligned N-doped MWCNT

This paper is dedicated to carbon nanotubes grown by electron cyclotron resonance plasma-enhanced chemical vapour deposition. It has been shown that carbon nanotubes (CNTs) can be grown at temperature as low as 550 °C by this technique. X-ray photoelectron spectroscopy and near-edge X-ray absorption fine structure spectroscopy were used to analyse nitrogen-doped CNTs. Independently of the synthesis temperature, about 4 at.% nitrogen are incorporated in the CNTs. A good correlation was found between XPS and NEXAFS results. Four components (397.3, 398.5, 400.8 and 402.5 eV) compose N 1s XPS spectra related to different chemical environments of nitrogen. This interpretation can be used as a simple check method of the presence of CNTs on as-deposited PECVD samples