Dissociative adsorption of O2 on negatively charged nitrogen-doped single-walled carbon nanotubes: first-principles calculations

Content Provider	Semantic Scholar
Author	Srivastava, Divya Laasonen, Kari
Copyright Year	2016
Abstract	Spin unrestricted density functional theory (DFT) calculations have been used to investigate the molecular and dissociative adsorption of O2 on achiral substitutional nitrogen-doped single-walled carbon nanotubes (N-SWNTs) with and without additional charges. Adsorption (dissociation) of O2 on the charged tubes is quite complex. The N-SWNTs with an additional electron with different orientations exhibit different behaviors. The armchair N-SWNTs carrying an extra electron have lower chemisorption (up to 0.6 eV) and reaction (up to 1.2 eV) energies for O2 compared to the corresponding neutral N-SWNTs. For (10, 10) N-SWNTs, the dissociation barrier decreases from 1.36 eV (in neutral) to 0.76 eV (in negatively charged). The reactivity of the armchair N-SWNTs with low nitrogen content can be increased by adding extra electrons. For the metallic zigzag N-SWNTs, an additional electron affects the O2 adsorption and dissociation marginally. However, negatively charged zigzag N-SWNTs, which are semiconducting when un-doped, have significantly lower O2 adsorption, reaction and dissociation barrier energies than the neutral N-SWNTs. We also studied the molecular and dissociative adsorption of O2 on (10, 10) single-walled nanotubes doped with two substitutional nitrogen atoms (N2-SWNTs), as a function of extra charge. The chemisorption and reaction energies decrease linearly with the increasing number of extra electrons. The barrier for O2 dissociation on N2-SWNTs is found to increase with the increasing number of additional electrons. Our results point out that the dissociative adsorption of an oxygen molecule on N-SWNTs depends on many parameters: curvature, chirality, and charge. The effect of additional charge on the reactivity of the N-doped SWNTs is rather independent of the tube diameter, but depends on the tube orientation.
Starting Page	84155
Ending Page	84163
Page Count	9
File Format	PDF HTM / HTML
DOI	10.1039/C6RA14023H
Volume Number	6
Alternate Webpage(s)	https://research.aalto.fi/files/11230705/Dissociative_adsorption.pdf
Alternate Webpage(s)	http://pubs.rsc.org/en/content/articlepdf/2016/ra/c6ra14023h
Alternate Webpage(s)	https://pubs.rsc.org/en/content/articlepdf/2016/ra/c6ra14023h
Alternate Webpage(s)	https://doi.org/10.1039/C6RA14023H
Language	English
Access Restriction	Open
Content Type	Text
Resource Type	Article