Enhancing thermal stability of n-type conduction in carbon nanotubes via cation replacement mediated by bicyclic guanidinium salts

Abstract

The development of thermally stable n-type carbon nanotubes (CNTs) is crucial for their implementation in pn junction devices. In previous work, we introduced an ion replacement technique to stabilize chemically p-doped CNTs, demonstrating the control of hole density and the stabilization of doped states through separate doping and anion replacement processes. This study extends the methodologies to n-type doping by substituting the cation with a specific dopant or stabilizer. The exceptional reduction capability of the cobalt-based complex was evident from the negative Seebeck coefficient, the markedly high electrical conductivity, and the reduction in work function of the doped CNTs. Additionally, the selection of the anion is critical for successful cation replacement, as explored through complex chemistry perspectives. The n-type CNTs, coordinated with bicyclic guanidinium cations, showed improved thermal stability compared to their as-doped counterparts. Lastly, we discuss the thermoelectric properties (with the power factor up to 100 μW m−1 K−2) as prospective applications for n-type CNTs in energy harvesting. This foundational work proposes a strategy for engineering n-type CNTs with optimized doping levels and enhanced stability.

Graphical abstract: Enhancing thermal stability of n-type conduction in carbon nanotubes via cation replacement mediated by bicyclic guanidinium salts

Supplementary files

Article information

Article type
Paper
Submitted
24 Mar 2025
Accepted
04 Jun 2025
First published
11 Jun 2025

J. Mater. Chem. C, 2025, Advance Article

Enhancing thermal stability of n-type conduction in carbon nanotubes via cation replacement mediated by bicyclic guanidinium salts

K. Kawasaki, M. Nishinaka, Y. Koshiba, A. Akiyama, Q. Wei, M. Funahashi and S. Horike, J. Mater. Chem. C, 2025, Advance Article , DOI: 10.1039/D5TC01263E

To request permission to reproduce material from this article, please go to the Copyright Clearance Center request page.

If you are an author contributing to an RSC publication, you do not need to request permission provided correct acknowledgement is given.

If you are the author of this article, you do not need to request permission to reproduce figures and diagrams provided correct acknowledgement is given. If you want to reproduce the whole article in a third-party publication (excluding your thesis/dissertation for which permission is not required) please go to the Copyright Clearance Center request page.

Read more about how to correctly acknowledge RSC content.

Social activity

Spotlight

Advertisements