Single-walled carbon nanotubes (SWCNTs) can be either metallic or semiconducting, making their separation critical for applications in nanoelectronics, biomedical materials, and solar cells. Herein, we investigate a novel solution-phase separation method based on click chemistry (azide-alkyne Huisgen cycloaddition) and determine its efficiency and scalability. In this method, metallic SWCNTs in metallic/semiconducting SWCNT mixtures are selectively functionalized with alkyne groups by being reacted with 4-propargyloxybenezenediazonium tetrafluoroborate. Subsequently, silica nanoparticles are functionalized with azide groups and reacted with alkyne-bearing metallic SWCNTs in the SWCNT mixture in the presence of a Cu catalyst. As a result, metallic SWCNTs are anchored on silica powder, whereas non-functionalized semiconducting SWCNTs remain in solution. Low-speed centrifugation effectively removes the silica powder with attached metallic SWCNTs, furnishing a solution of highly pure semiconducting SWCNTs, as confirmed by Raman and UV-vis/near-infrared absorption measurements. This novel separation scheme exhibits the advantage of simultaneously separating both metallic and semiconducting SWCNTs from their mixtures, being cost-effective and therefore applicable at an industrial scale.
Bibliographical noteFunding Information:
This work was supported by the Basic Science Research Program of the National Research Foundation of Korea (NRF) and funded by the Ministry of Education ( NRF-2016R1D1A1B03934986 ) and the Korea Institute of Energy Technology Evaluation and Planning (KETEP) and the Ministry of Trade , Industry & Energy (MOTIE) of the Republic of Korea (No. 20162010104190 ).
© 2017 Elsevier B.V.
- Click chemistry
- Copper catalyst
- SWCNT separation
- 1,3-dipolar cycloaddition