Outer tube-selectively boron-doped double-walled carbon nanotubes for thermoelectric applications

May 02, 2020

Carbon nanotubes, the tiny hollow tube of hexagonal carbon lattices has been touted as one of the most promising materials for building items with fascinating electrical, thermal and mechanical properties. Selective functionality is realized by adding elements to the carbon nanotubes to make transistors, composite additives, field emitters and transparent conductive films. Carbon nanotubes doped with boron makes the structure of the tubes more functional while increasing the ability to modulate the electrical properties. Boron-doping into coaxially aligned two single-walled carbon nanotubes (double-walled carbon nanotubes :DWNTs) show promise for use in electronic devices, composite materials, energy storage and power generation materials.

A research group led by Hiroyuki Muramatsu of Shinshu University succeeded in selectively doping the outer nanotube of the DWNTs with boron. Previously, there was no method to control the incorporation of boron atoms to carbon nanotubes. The tubes would fuse together or the structure would drastically change through treatments of boron-doping, frustrating researchers. In this study, Muramatsu and his team were able to selectively add boron to the outer tubes of DWNTs. This significantly increased the electrical conductivity and the Seebeck coefficient which resulted in a highly enhanced thermoelectric performance of the DWNTs.

This advancement in technique allows for an extremely effective method to add functionality such as high electrical conductivity, chemical activation and improvement of thermoelectric properties while maintaining the function of the inner CNT. Muramatsu and his team succeeded in discovering the conditions for intricately doping boron on a single outermost layer of CNT without changing the coaxial structure of DWNTs. Only then were they able to actually demonstrate and confirm the characteristics of the synthesized DWNTs.

In the future boron-doped DWNTs could be used in thermoelectric applications to harvest waste heat for electricity generation and other advanced applications. However, DWNTs are still not very well understood. Muramatsu believes that through fundamental research and understanding the basic properties of outer tube-selectively boron-doped DWNTs, more applications can be found while enhancing performance relevant to various applications. The ultimate goal is to strategically use the characteristics of the structure and physical properties of DWNTs to add unique functions and characteristics. New principles and methods must be investigated in detail to establish a more selective high-concentration doping method and study its effect on the structure and function.

Shinshu University

Related Carbon Nanotubes Articles from Brightsurf:

How plantains and carbon nanotubes can improve cars
Researchers from the University of Johannesburg have shown that plantain, a starchy type of banana, is a promising renewable source for an emerging type of lighter, rust-free composite materials for the automotive industry.

New production method for carbon nanotubes gets green light
A new method of producing carbon nanotubes -- tiny molecules with incredible physical properties used in touchscreen displays, 5G networks and flexible electronics -- has been given the green light by researchers, meaning work in this crucial field can continue.

Growing carbon nanotubes with the right twist
Researchers synthetize nanotubes with a specific structure expanding previous theories on carbon nanotube growth.

Research shows old newspapers can be used to grow carbon nanotubes
New research has found that old newspaper provide a cheap and green solution for the bulk production of single walled carbon nanotubes.

Clean carbon nanotubes with superb properties
Scientists at Aalto University, Finland, and Nagoya University, Japan, have found a new way to make ultra-clean carbon nanotube transistors with superior semiconducting properties.

Dietary fiber effectively purifies carbon nanotubes
A dietary fiber can help separate out semiconducting carbon nanotubes used for making transistors for flexible electronics.

Why modified carbon nanotubes can help the reproducibility problem
Scientists at Tokyo Institute of Technology (Tokyo Tech) conducted an in-depth study on how carbon nanotubes with oxygen-containing groups can be used to greatly enhance the performance of perovskite solar cells.

Tensile strength of carbon nanotubes depends on their chiral structures
Single-walled carbon nanotubes should theoretically be extremely strong, but it remains unclear why their experimental tensile strengths are lower and vary among nanotubes.

New study reveals carbon nanotubes measurement possible for the first time
Swansea University scientists report an entirely new approach to manipulation of carbon nanotubes that allows physical measurements to be made on carbon nanotubes that have previously only been possible by theoretical computation.

Neural networks will help manufacture carbon nanotubes
A team of scientists from Skoltech's Laboratory of Nanomaterials proposed a neural-network-based method for monitoring the growth of carbon nanotubes, preparing the ground for a new generation of sophisticated electronic devices.

Read More: Carbon Nanotubes News and Carbon Nanotubes Current Events
Brightsurf.com is a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for sites to earn advertising fees by advertising and linking to Amazon.com.