Eur. Phys. J. D (2015) 69: 185
https://doi.org/10.1140/epjd/e2015-60172-x

Regular Article

Adsorption of gases from SF₆ decomposition on aluminum-doped SWCNTs: a density functional theory study

¹ State Key Laboratory of Power Transmission Equipment & System Security and New Technology, Chongqing University, Chongqing 400044, P.R. China.
² School of Electrical Engineering, Wuhan University, Wuhan 430072, P.R. China.
³ Liupanshui Power Supply Bureau of Guizhou Power Grid Corporation, Guizhou 553000, P.R. China

^a e-mail: xiaoxing.zhang@outlook.com

Received: 14 March 2015
Received in final form: 10 June 2015
Published online: 28 July 2015

Abstract

Adsorption of gases produced by SF₆ decomposition (i.e., SO₂, H₂S, SOF₂, SO₂F₂, and CF₄) by aluminum-doped zigzag (8, 0) single-walled carbon nanotubes (Al-SWCNTs) was investigated based on first-principles density functional theory (DFT). Different binding sites were considered to determine the most stable structures. Furthermore, adsorption energy, density of state, band structure, frontier molecular orbital, and population were analyzed to interpret the mechanism of gas adsorption on the surface of Al-SWCNTs. The calculation results predicted that the Al atom acted as an active site to adsorb the SF₆ decomposition products in the adsorption process. SO₂, H₂S, and CF₄ molecules were adsorbed on the sidewall of Al-SWCNTs by physisorption, whereas SOF₂ and SO₂F₂ were molecularly chemisorbed. Conductivity of Al-SWCNTs was increased when the gas molecules of SO₂, H₂S, and SO₂F₂ were adsorbed. Conversely, SOF₂ adsorption slightly decreased the conductivity of the adsorption system. Al-SWCNTs were insensitive to CF₄. The different responses in conductivity of Al-SWCNTs for different gas molecule adsorptions present a potential selective and sensitive gas detection sensor.