Comparison of Synchrotron and Laboratory X-ray Sources in Photoelectron Spectroscopy Experiments for the Study of Nitrogen-Doped Carbon Nanotubes

The chemical composition and stoichiometry of vertically aligned arrays of nitrogen-doped multi-walled carbon nanotubes (N-CNTs) were studied by photoelectron spectroscopy using laboratory and synchrotron X-ray sources. We performed careful deconvolution of high-resolution core-level spectra to quantify pyridine/pyrrole-like defects in N-CNTs, which are a key factor in the efficiency of the piezoelectric response for this material. It is shown that the XPS method makes it possible to estimate the concentration and type of nitrogen incorporation (qualitatively and quantitatively) in the “N-CNT/Mo electrode” system using both synchrotron and laboratory sources. The obtained results allow us to study the effect of the nickel catalytic layer thickness on the concentration of pyridine/pyrrole-like nitrogen and piezoelectric response in the nanotubes.