TOWARDS THE SINGLE-WALLED B- AND/OR N-DOPED CARBON NANOTUBES

Abstract

Soon after the discovery of carbon nanotubes (CNTs) in the early 1990's, the B-and/or N-doped CNTs began to attract increasing interest owing to their modified structural, physical and chemical properties. In comparison with the multi-walled nanotubes and nanofibers, substitutional doping of the single-walled nanotubes (SWNTs) has proved to be much more difficult, and it is only in very recent years that some experimental studies concerning the B-and/or N-doped SWNTs are emerging. This paper intends to provide an up-to-date overview of current research on the doped SWNTs, with scopes covering both the binary system of CB x -and CN x -SWNTs and the ternary B x C y N z -SWNTs. A survey of the latest achievements in the syntheses of doped SWNTs through either the direct syntheses methods or the post-synthetic substitution reaction route is first presented; then the aspects concerning their structural features, elemental compositions, dopants bonding configuration and atomic distributions, as well as their physical and chemical properties are discussed.

Special electronic structures and quantum conduction of B/P co-doping carbon nanotubes under electric field using the first principle

“…Chemical doping also can convert the metallic SWTN to semiconductor, which has been discussed by Zhi Xu [17] whose study showed that those boron/nitrogen co-doping metallic single wall carbon nanotubes will be converted to semiconductors. In contrast to the study of W. L. WANG et al [18], our results demonstrated substitutional P dopants within the nanotube C lattices is sp 3 coordinated rather than sp 2 coordinated. The constituting B, C and N elements are homogenously distributed within the SWNTs tube shells with no appreciable phase-separated B N and C domains, which have been synthesized by using the Bias-Assisted Hot filament chemical vapor deposition [19].…”

Conducting carbonized polyaniline nanotubes

“…The discovery of carbon nanotubes (CNTs) has had a great impact on modern nanotechnology [1]. During the last decade, it has been revealed that the nitrogen-containing carbon nanotubes (NCNTs) possess outstanding physicochemical properties when compared with ordinary CNTs [2,3]. NCNTs were found to be important in the fabrication of new catalysts and fuel cells [4][5][6][7].…”

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

“…Chemical doping has shown great success in silicon‐based semiconductors. This strongly implies that the electronic properties of SWCNTs should be tailored by appropriate doping during the synthesis process; just like that which has been used in Si‐based systems, nitrogen, boron, and phosphorous have been tried as dopants in SWCNTs 28–32. Since nitrogen and boron have similar atomic sizes to carbon, it is much easier for them to be inserted into the carbon structures.…”

“…Until now, most reports have been about the doping of multiwalled carbon nanotubes (MWCNTs), possibly due to their higher structure tolerance 33. Bulk syntheses of doped SWCNTs have been performed by substitution reactions,34 arc discharge,35 laser ablation,36 and chemical vapor deposition (CVD) 28, 37. Xu et al proved that B/N co‐doping turns all SWCNTs to be semiconducting,29 while other reports have confirmed that carbon nanotubes behave metallically when doped by either B or N alone 30, 31.…”