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: email@example.com
Received in final form: 10 June 2015
Published online: 28 July 2015
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.
Key words: Molecular Physics and Chemical Physics
© EDP Sciences, Società Italiana di Fisica, Springer-Verlag 2015