Analysis of structure and electrochemical characteristics of multi-walled carbon nanotubes doped with nitrogen using ion irradiation

Abstract

Comparative study of the electronic structure and electrochemical characteristics of multi-walled carbon nanotubes (MWCNTs) doped with nitrogen using synthesis with a nitrogen-containing precursor (N-MWCNTs), as well as using N2+ ion irradiation with an average energy of ∼ 5 keV was provided. Using XPS, it was shown that the surface of irradiated MWCNTs contains 5.6 at.% nitrogen, which is predominantly in the pyridine and pyrrole configurations, as well as there are 12.8 at.% of oxygen in carbon–oxygen and nitrogen–oxygen chemical bonds. The N-MWCNTs surface contains 2.5 at.% nitrogen, ∼ 25% of which presents in the form of N2. An analysis of the electrochemical characteristics showed that irradiated carbon nanotubes have higher specific capacitance and rate capability. It is shown that the increase in characteristics is provided due to reversible redox processes occurring with the participation of nitrogen and oxygen groups on the surface of carbon nanotubes.