Polyoxometalate steric hindrance driven chirality-selective separation of subnanometer carbon nanotubes

Xusheng Yang; Chao Zhu; Lianduan Zeng; Weiyang Xue; Luyao Zhang; Lei Zhang; Kaitong Zhao; Min Lyu; Lei Wang; Yuan-Zhu Zhang; Xiao Wang; Yan Li; Feng Yang

doi:10.1039/d2sc01160c

Polyoxometalate steric hindrance driven chirality-selective separation of subnanometer carbon nanotubes

Chem Sci. 2022 Apr 25;13(20):5920-5928. doi: 10.1039/d2sc01160c. eCollection 2022 May 25.

Authors

Xusheng Yang¹, Chao Zhu¹, Lianduan Zeng^{2

3}, Weiyang Xue¹, Luyao Zhang¹, Lei Zhang¹, Kaitong Zhao¹, Min Lyu⁴, Lei Wang¹, Yuan-Zhu Zhang¹, Xiao Wang², Yan Li^{4

5

6}, Feng Yang¹

Affiliations

¹ Department of Chemistry, Guangdong Provincial Key Laboratory of Catalysis, Southern University of Science and Technology Shenzhen Guangdong 518055 China yangf3@sustech.edu.cn.
² Shenzhen Key Laboratory of Nanobiomechanics, Shenzhen Institutes of Advanced Technology, Chinese Academy of Sciences Shenzhen 518055 China xiao.wang@siat.ac.cn.
³ Nano Science and Technology Institute, University of Science and Technology of China Suzhou 215000 China.
⁴ Beijing National Laboratory for Molecular Science, Key Laboratory for the Physics and Chemistry of Nanodevices, State Key Laboratory of Rare Earth Materials Chemistry and Applications, College of Chemistry and Molecular Engineering, Peking University Beijing 100871 China yanli@pku.edu.cn.
⁵ Peking University Shenzhen Institute Shenzhen 518057 China.
⁶ PKU-HKUST ShenZhen-HongKong Institution Shenzhen 518057 China.

Abstract

Subnanometer single-chirality single-walled carbon nanotubes (SWCNTs) are of particular interest in multiple applications. Inspired by the interdisciplinary combination of redox active polyoxometalates and SWCNTs, here we report a cluster steric hindrance strategy by assembling polyoxometalates on the outer surface of subnanometer SWCNTs via electron transfer and demonstrate the selective separation of monochiral (6,5) SWCNTs with a diameter of 0.75 nm by a commercially available conjugated polymer. The combined use of DFT calculations, TEM, and XPS unveils the mechanism that selective separation is associated with tube diameter-dependent interactions between the tube and clusters. Sonication drives the preferential detachment of polyoxometalate clusters from small-diameter (6,5) SWCNTs, attributable to weak tube-cluster interactions, which enables the polymer wrapping and separation of the released SWCNTs, while strong binding clusters with large-diameter SWCNTs provide steric hindrance and block the polymer wrapping. The polyoxometalate-assisted modulation, which can be rationally customized, provides a universal and robust pathway for the separation of SWCNTs.