Metal free, end-opened, selective nitrogen-doped vertically aligned carbon nanotubes by a single step in situ low energy plasma process

Abstract

We report a novel single step in situ process of growth and nitrogen-electron cyclotron resonance plasma treatment of vertically aligned multi walled carbon nanotubes (VA-MWCNTs) that leads to concurrent end opening by metal cap removal, nitrogen incorporation and intercalation along with substitution at graphitic sites resulting in n-type electronic doping. Microscopic and spectroscopic evaluations of the nitrogen treated MWCNTs reveal negligible iron content with significant conservation of both structure and alignment. The nitrogen induced electronic change increases distinct p* states as evidenced by Near Edge X-ray Absorption Fine Structure (NEXAFS) and 5 cm À1 downshift of G-band, as observed from Raman spectroscopy, confirm n-type doping. The combined effect of plasma activation (both cavities and surface of the end opened VA-MWCNTs) and n-type doping enhances the field emission performance of the CNTs resulting in high current density (15 mA cm À2) at low applied voltage of 1.5 V mm À1 with low turn on and threshold electric fields (E to-0.52 and E th-0.76 V mm À1). This low energy highly controllable plasma has great implications not only in the fabrication of various n-type materials and bio related application but also many other interesting areas for cost effective energy related applications.

Nitrogen‐Coordinated Single Cobalt Atom Catalysts for Oxygen Reduction in Proton Exchange Membrane Fuel Cells

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“…In fact, the magnetic field induced electron 11 confinement in the ECR configuration generates high temperature electron distribution tails of nearly 30 eV which lead to a relatively high degree of N2 dissociation without a significant increase in the potential or ion bombardment energies. 53 Considering that for both set of samples, the treatment time was kept the same; the ECR process produced significantly higher pyridinic nitrogen as compared to the rf-PECVD process and as such corroborates the results presented by Zhao et al 51 Using molecular dynamics, Åhlgren et al have…”

One-dimensional nitrogen-containing carbon nanostructures

“…A single step in situ process of growth and nitrogen-electron cyclotron resonance plasma treatment of vertically aligned MWCNTs that leads to concurrent end opening by metal cap removal, nitrogen incorporation and intercalation along with substitution at graphitic sites resulting in n-type electronic doping, has been reported by Iyer et al (Fig. 7) [270].…”