Header

UZH-Logo

Maintenance Infos

Characterizing and understanding divalent adsorbates on carbon nanotubes with ab initio and classical approaches: size, chirality, and coverage effects


Kroes, Jaap M H; Pietrucci, Fabio; Curioni, Alessandro; Andreoni, Wanda (2014). Characterizing and understanding divalent adsorbates on carbon nanotubes with ab initio and classical approaches: size, chirality, and coverage effects. Journal of Chemical Theory and Computation, 10(10):4672-4683.

Abstract

The study of oxygen chemisorption on single-walled carbon nanotubes generally relies on simple atomistic models and hence hampers the possibility to understand whether nanotube size or adduct concentration have a role in determining the surface-adsorbate interaction. Our large-scale DFT-based simulations show that structural and electronic properties as well as diffusion barriers strongly depend on both nanotube diameter and adsorbate concentration. Our atomistic models cover nanotube of different chirality with diameters from 0.6 to 1.5 nm and oxygen concentration from 0.1 to 1%. In particular, the tendency to cluster increases with concentration and stabilizes ether (ET) groups but affects hopping barriers only to a minor extent. Significant differences with graphene are found, also for 1.5 nm diameter nanotubes. Extension to species isoelectronic to oxygen reveals dissimilarities, and especially for sulfur that tends to form epoxides (EP), to diffuse more easily and to rapidly close the energy gap for increasing concentration. The relative ET-EP stability can be described in terms of the bare-bond curvature, a concentration-dependent chemical descriptor here introduced. Comparison of these DFT calculations-using different exchange-correlation functionals-and our additional investigation with a reactive force-field (ReaxFF) clarifies several similarities but also discrepancies between the predictions of the two schemes.

Abstract

The study of oxygen chemisorption on single-walled carbon nanotubes generally relies on simple atomistic models and hence hampers the possibility to understand whether nanotube size or adduct concentration have a role in determining the surface-adsorbate interaction. Our large-scale DFT-based simulations show that structural and electronic properties as well as diffusion barriers strongly depend on both nanotube diameter and adsorbate concentration. Our atomistic models cover nanotube of different chirality with diameters from 0.6 to 1.5 nm and oxygen concentration from 0.1 to 1%. In particular, the tendency to cluster increases with concentration and stabilizes ether (ET) groups but affects hopping barriers only to a minor extent. Significant differences with graphene are found, also for 1.5 nm diameter nanotubes. Extension to species isoelectronic to oxygen reveals dissimilarities, and especially for sulfur that tends to form epoxides (EP), to diffuse more easily and to rapidly close the energy gap for increasing concentration. The relative ET-EP stability can be described in terms of the bare-bond curvature, a concentration-dependent chemical descriptor here introduced. Comparison of these DFT calculations-using different exchange-correlation functionals-and our additional investigation with a reactive force-field (ReaxFF) clarifies several similarities but also discrepancies between the predictions of the two schemes.

Statistics

Altmetrics

Downloads

0 downloads since deposited on 12 Jan 2017
0 downloads since 12 months

Additional indexing

Item Type:Journal Article, refereed, original work
Communities & Collections:04 Faculty of Medicine > University Hospital Zurich > Clinic for Oncology
Dewey Decimal Classification:610 Medicine & health
Language:German
Date:14 October 2014
Deposited On:12 Jan 2017 13:43
Last Modified:22 Jan 2017 06:03
Publisher:American Chemical Society (ACS)
ISSN:1549-9618
Publisher DOI:https://doi.org/10.1021/ct500701n
PubMed ID:26588158

Download