Nitrogen‐Doped Single‐Walled Carbon Nanotubes Grown on Substrates: Evidence for Framework Doping and Their Enhanced Properties

Abstract

Nitrogen-doped single-walled carbon nanotubes (SWCNTs) are synthesized directly on silicon and quartz substrates through a normal chemical vapor deposition (CVD) method. Thermogravimetry mass spectrometry measurements and Raman spectroscopy give fi rm evidence for framework nitrogen doping. X-ray-photoelectron-spectroscopy analysis further obtains the bonding style of the nitrogen atoms in the carbon framework. The nitrogen doping signifi cantly changes the properties of the SWCNTs. All of the tubes behave like metallic tubes in fi eld-effect transistors. The doped nitrogen atoms introduce a stronger affi nity for the SWCNTs to metal nanoparticles. Compared with pristine SWCNTs, the nitrogen-doped tubes show enhanced sensitivity and selectivity for electrochemical detection of some electrophilic species including O 2 , H 2 O 2 , and Fe 3 + . They also present improved electrocatalytic activity for oxygen reduction. These unique properties of the nitrogendoped SWCNTs endow them with important potential applications in various fi elds.

Spectroscopic Fingerprints of Graphitic, Pyrrolic, Pyridinic, and Chemisorbed Nitrogen in N-Doped Graphene

“…The calculated binding energy of pyrrolic nitrogen was 399.7 eV. Liu et al synthesized nitrogen-doped single-walled carbon nanotubes on silicon and quartz substrates and observed a secondary peak at 399.8 eV, in addition to the peak from graphitic nitrogen at 401.8 eV . They attributed this secondary peak to pyridinic N, but our results suggest that it is more likely to have originated from pyrrolic nitrogen.…”

Identification of Nitrogen Dopants in Single-Walled Carbon Nanotubes by Scanning Tunneling Microscopy

“…These macroscopic measurements are in strong agreement with the nanometer-scale data presented in Figure , which exhibits two peaks at the Fermi level and close to the van Hove singularity. Finally, it is to be noted that the current–voltage characteristics measured for isolated nitrogen-doped nanotubes have demonstrated that n-type doping is achievable, provided that the concentration of substitutional nitrogen atom, like the case displayed in Figure , is sufficient. , …”

Effect of N-Doping of Single-Walled Carbon Nanotubes on Bioelectrocatalysis of Laccase

“…These behaviors are similar to those observed in previous reports. 48 Thus, Ndoped SWCNTs had been successfully synthesized, and from the appearance of the broad G − and BFW peaks, it was clear that the N dopant concentration increased with the volume ratio of AN in the mixed AN and EtOH solution. The Raman peak at around 2700 cm −1 corresponded to the second-order Raman spectrum of a crystalline sp 2 -hydribized structure carbon, which is termed the 2D (G′)-band.…”