Zhang Ruixi, Levshov Dmitry, Otsuka Keigo, Feng Ya, Zheng Yongjia, Kauppinen Esko I, Chiashi Shohei, Wenseleers Wim, Cambré Sofie, Xiang Rong, Maruyama Shigeo
Department of Mechanical Engineering, The University of Tokyo, Tokyo, 113-8656, Japan.
Department of Bioengineering, The University of Tokyo, Tokyo, 113-8656, Japan.
Small. 2025 Feb;21(8):e2407271. doi: 10.1002/smll.202407271. Epub 2024 Oct 31.
The controlled synthesis of 1D van der Waals (1D vdW) heterostructures, specifically single-walled carbon nanotubes encapsulated within boron nitride nanotubes (SWCNT@BNNT), presents a challenge due to an incomplete understanding of the factors influencing BNNT growth. This study investigates the growth yield of SWCNT@BNNT heterostructures produced using zeolite-supported SWCNT templates on SiO-coated Transmission Electron Microscopy (TEM) grids, which enable in situ synthesis and thorough evaluation of each step without compromising the nanotube structure. The high-resolution TEM analysis reveals a significant improvement in BNNT coverage on individual nanotubes, increasing from 9% to 42%, through optimization of the ammonia borane precursor amount. A thorough comparison of BNNT growth efficiency is performed using zeolite-supported SWCNT templates against the current benchmark of free-standing SWCNT films, highlighting comparable synthesis yields despite different morphologies and SWCNT diameter distributions. By integrating all Raman and TEM data from the studied SWCNT@BNNT samples, a correlation between BNNT coverage and the intensity of the buckling R-mode of BNNTs is established, providing a reliable criterion for evaluating BNNT growth efficiency in 1D vdW heterostructures. This work advances the understanding and characterization of 1D vdW heterostructures, offering insights into synthesizing hetero-nanotubes using other types of SWCNT templates and paving the way for their diverse applications.
一维范德华（1D vdW）异质结构的可控合成，特别是氮化硼纳米管封装的单壁碳纳米管（SWCNT@BNNT），由于对影响氮化硼纳米管生长的因素了解不全面而面临挑战。本研究调查了在SiO涂层透射电子显微镜（TEM）网格上使用沸石负载的单壁碳纳米管模板制备的SWCNT@BNNT异质结构的生长产率，该模板能够原位合成并对每个步骤进行全面评估，同时不破坏纳米管结构。高分辨率透射电子显微镜分析表明，通过优化硼烷氨前体的用量，单个纳米管上的氮化硼纳米管覆盖率显著提高，从9%提高到42%。使用沸石负载的单壁碳纳米管模板与独立单壁碳纳米管薄膜的当前基准进行了氮化硼纳米管生长效率的全面比较，突出了尽管形态和单壁碳纳米管直径分布不同，但合成产率相当。通过整合所研究的SWCNT@BNNT样品的所有拉曼和透射电子显微镜数据，建立了氮化硼纳米管覆盖率与氮化硼纳米管屈曲R模式强度之间的相关性，为评估一维范德华异质结构中氮化硼纳米管的生长效率提供了可靠标准。这项工作推进了对一维范德华异质结构的理解和表征，为使用其他类型的单壁碳纳米管模板合成异质纳米管提供了见解，并为其多样化应用铺平了道路。
