Synthesis and application of 1D vdW heterostructures based on single-walled carbon nanotubes

Speaker: Prof. Shigeo Maruyama, The University of Tokyo, Japan

Abstract:  We have demonstrated the atomically precise one-dimensional (1D) van der Waals (vdW) heterostructure: single-walled carbon nanotubes (SWCNTs), boron nitride nanotubes (BNNTs), and molybdenum disulfide (MoS2) sequentially wrapped in the radial direction, by chemical vapor deposition in 2020 [1,2]. One of the obvious extensions of this work is the use of BNNT-SWCNT, which has superior semiconductor properties such as field effect transistors [3]. We have developed various optical characterization techniques for BNNT-SWCNT for the growth optimization and quality control of BNNT in several types of SWCNT [4-5]. Finally, we can discuss BNNT wrapping through Raman features of SWCNT. Strain in SWCNT can be clearly demonstrated in the G-G’(2D) map [6].

We have optimized CVD conditions for various metal dichalcogenides such as tungsten disulfide (WS2), niobium disulfide (NbS2), and molybdenum diselenide (MoSe2) so far, in addition to the original MoS2. Furthermore, we broaden the concept of 1D vdW heterostructure by combining 2 transition metal species. We can combine two TMDs: axial junction of WS2-MoS2 nanotubes and alloyed nanotubes such as {WxMo(1-x)}S2 [7].

Finally, we will discuss the various Yanus TMD nanotubes templated by SWCNT-BNNT. We employ the hydrogen plasma technique to demonstrate the single-walled Yanus MoSSe with a diameter of around 8-10 nm, starting from MoS2 nanotubes. The inside S and outside Se configuration is apparently stable [8].

References: [1] R. Xiang, et al., Science 2020, 367, 537. [2] Y. Zheng, et al., P. Natl. Acad. Sci. 2021, 118, e2107295118. [3] K. Otsuka, et al., Nano Res. 2023, 16, 12840-12848. [4] M. Liu, et al., ACS Nano 2021, 15, 8418. [5] R. Zhang, et al., Carbon 2022, 199, 407. [6] S. Wang, et al., ACS Nano 2024, 18, 9917. [7] Y. Zheng, et al., in preparation. [8] C. Yang, et al., in preparation.

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