Differentiating Confined from Adsorbed Water in Single-Walled Carbon Nanotubes via Electronic Transport

Fuente: arXiv
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Main Authors: Pashayev, Said, Lhermerout, Romain, Roblin, Christophe, Alibert, Eric, Jelinek, Remi, Izard, Nicolas, Jabbarov, Rasim, Henn, Francois, Noury, Adrien
Format: Preprint
Published: 2024
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author Pashayev, Said
Lhermerout, Romain
Roblin, Christophe
Alibert, Eric
Jelinek, Remi
Izard, Nicolas
Jabbarov, Rasim
Henn, Francois
Noury, Adrien
author_facet Pashayev, Said
Lhermerout, Romain
Roblin, Christophe
Alibert, Eric
Jelinek, Remi
Izard, Nicolas
Jabbarov, Rasim
Henn, Francois
Noury, Adrien
contents In this article, we show that it is possible to differentiate between water adsorbed on the outside of a single-walled carbon nanotube and that confined inside. To this aim, we measured the electronic transport of a carbon nanotube based field effect transistor (CNTFET) constructed with an isolated single carbon nanotube subjected to controlled environments. More precisely, this distinction is made possible by observing the evolution of the transfer characteristic as a function of the electric field imposed by the gate voltage. It appears that the presence of water results in a displacement of the electrical neutrality point, corresponding to a charge transfer between the nanotube and its environment. Using this approach, we demonstrate the existence of 3 types of water molecules: (i) chemically adsorbed on the SiO\textsubscript{2} surface of the substrate, i.e., forming silanol groups; (ii) physically adsorbed outside next to the nanotube; and (iii) confined inside the nanotube. The first one can only be eliminated by high temperature treatment under vacuum, the second one desorbs in a moderate vacuum at room temperature, while the confined water can be removed at room temperature at higher vacuum, i.e. $10^{-3}$ mbar. We also observe that both water adsorption outside and water confinement inside the nanotube are spontaneous and rather fast, i.e. less than 1 minute in our experimental conditions, while removing the water adsorbed outside and confined inside takes much longer, i.e. 40-60 minutes, thus indicating that water confinement is thermodynamically favorable. It is also shown that the metallicity of the nanotube has no qualitative influence on its interaction with water. Our results experimentally prove the stronger affinity of water for the inner surface of CNT than for the outer one.
format Preprint
id arxiv_https___arxiv_org_abs_2412_11703
institution arXiv
publishDate 2024
record_format arxiv
spellingShingle Differentiating Confined from Adsorbed Water in Single-Walled Carbon Nanotubes via Electronic Transport
Pashayev, Said
Lhermerout, Romain
Roblin, Christophe
Alibert, Eric
Jelinek, Remi
Izard, Nicolas
Jabbarov, Rasim
Henn, Francois
Noury, Adrien
Soft Condensed Matter
In this article, we show that it is possible to differentiate between water adsorbed on the outside of a single-walled carbon nanotube and that confined inside. To this aim, we measured the electronic transport of a carbon nanotube based field effect transistor (CNTFET) constructed with an isolated single carbon nanotube subjected to controlled environments. More precisely, this distinction is made possible by observing the evolution of the transfer characteristic as a function of the electric field imposed by the gate voltage. It appears that the presence of water results in a displacement of the electrical neutrality point, corresponding to a charge transfer between the nanotube and its environment. Using this approach, we demonstrate the existence of 3 types of water molecules: (i) chemically adsorbed on the SiO\textsubscript{2} surface of the substrate, i.e., forming silanol groups; (ii) physically adsorbed outside next to the nanotube; and (iii) confined inside the nanotube. The first one can only be eliminated by high temperature treatment under vacuum, the second one desorbs in a moderate vacuum at room temperature, while the confined water can be removed at room temperature at higher vacuum, i.e. $10^{-3}$ mbar. We also observe that both water adsorption outside and water confinement inside the nanotube are spontaneous and rather fast, i.e. less than 1 minute in our experimental conditions, while removing the water adsorbed outside and confined inside takes much longer, i.e. 40-60 minutes, thus indicating that water confinement is thermodynamically favorable. It is also shown that the metallicity of the nanotube has no qualitative influence on its interaction with water. Our results experimentally prove the stronger affinity of water for the inner surface of CNT than for the outer one.
title Differentiating Confined from Adsorbed Water in Single-Walled Carbon Nanotubes via Electronic Transport
topic Soft Condensed Matter
url https://arxiv.org/abs/2412.11703