Nitrogen-doped carbon nanotubes (N-CNTs) can be produced through five main methods; chemical vapor deposition (CVD),[1][2] high-temperature and high-pressure reactions, gas-solid reaction of amorphous carbon with NH3 at high temperature,[3] solid reaction,[4] and solvothermal synthesis.[5]
Details
editN-CNTs can also be prepared by a CVD method of pyrolyzing melamine under Ar at elevated temperatures of 800–980 °C. However synthesis by CVD of melamine results in the formation of bamboo-structured CNTs. XPS spectra of grown N-CNTs reveal nitrogen in five main components, pyridinic nitrogen, pyrrolic nitrogen, quaternary nitrogen, and nitrogen oxides. Furthermore, synthesis temperature affects the type of nitrogen configuration.[2]
Nitrogen doping plays a pivotal role in lithium storage, as it creates defects in the CNT walls allowing for Li ions to diffuse into interwall space. It also increases capacity by providing more favorable bind of N-doped sites. N-CNTs are also much more reactive to metal oxide nanoparticle deposition which can further enhance storage capacity, especially in anode materials for Li-ion batteries.[6] However boron-doped nanotubes have been shown to make batteries with triple capacity.[7]
References
edit- ^ Kouvetakis, J.; Todd, M.; Wilkens, B.; Bandari, A.; Cave, N. (1994). "Novel Synthetic Routes to Carbon-Nitrogen Thin Films". Chemistry of Materials. 6 (6): 811–814. doi:10.1021/cm00042a018.
- ^ a b Zhong, Y.; Jaidann, M.; Zhang, Y.; Zhang, G.; Liu, H.; Ioan Ionescu, M.; Li, R.; Sun, X.; Abou-Rachid, H.; Lussier, L. S. (2010). "Synthesis of high nitrogen doping of carbon nanotubes and modeling the stabilization of filled DAATO@CNTs (10,10) for nanoenergetic materials". Journal of Physics and Chemistry of Solids. 71 (2): 134–139. Bibcode:2010JPCS...71..134Z. doi:10.1016/j.jpcs.2009.07.030.
- ^ Yin, L. -W.; Bando, Y.; Li, M. -S.; Liu, Y. -X.; Qi, Y. -X. (2003). "Unique Single-Crystalline Beta Carbon Nitride Nanorods". Advanced Materials. 15 (21): 1840–1844. doi:10.1002/adma.200305307.
- ^ Oku, T.; Kawaguchi, M. (2000). "Microstructure analysis of CN-based nanocage materials by high-resolution electron microscopy". Diamond and Related Materials. 9 (3–6): 906–910. Bibcode:2000DRM.....9..906O. doi:10.1016/S0925-9635(99)00359-3.
- ^ Guo, Q.; Xie, Y.; Wang, X.; Zhang, S.; Hou, T.; Lv, S. (2004). "Synthesis of carbon nitride nanotubes with the C3N4 stoichiometry via a benzene-thermal process at low temperatures Electronic Supplementary Information (ESI) available: XRD patterns". Chemical Communications (1): 26. doi:10.1039/B311390F.
- ^ Shin, W. H.; Jeong, H. M.; Kim, B. G.; Kang, J. K.; Choi, J. W. (2012). "Nitrogen-Doped Multiwall Carbon Nanotubes for Lithium Storage with Extremely High Capacity". Nano Letters. 12 (5): 2283–8. Bibcode:2012NanoL..12.2283S. doi:10.1021/nl3000908. PMID 22452675.
- ^ "Doped nanotubes boost lithium battery power three-fold." The Register. 14 February 2013.