title: Theoretical calculation of the gas-sensing properties of Pt-decorated carbon nanotubes.
abstract: The gas-sensing properties of Pt-decorated carbon nanotubes (CNTs), which provide a foundation for the fabrication of sensors, have been evaluated. In this study, we calculated the gas adsorption of Pt-decorated (8,0) single-wall CNTs (Pt-SWCNTs) with SO2, H2S, and CO using GGA/PW91 method based on density functional theory. The adsorption energies and the changes in geometric and electronic structures after absorption were comprehensively analyzed to estimate the responses of Pt-SWCNTs. Results indicated that Pt-SWCNTs can respond to the three gases. The electrical characteristics of Pt-SWCNTs show different changes after adsorption. Pt-SWCNTs donate electrons and increase the number of hole carriers after adsorbing SO2, thereby enhancing its conductivity. When H2S is adsorbed on CNTs, electrons are transferred from H2S to Pt-SWCNTs, converting Pt-SWCNTs from p-type to n-type sensors with improved conductivity. However, Pt-SWCNTs obtain electrons and show decreased conductivity when reacted with CO gas.
authors.affiliation: State Key Laboratory of Power Transmission Equipment & System Security and New Technology, Chongqing University, Shapingba District, Chongqing 400044, China. zhxx@cqu.edu.cn.
authors.forename: Xiaoxing
authors.initials: X
authors.lastname: Zhang
authors.forename: Ziqiang
authors.initials: Z
authors.lastname: Dai
authors.forename: Li
authors.initials: L
authors.lastname: Wei
authors.forename: Naifeng
authors.initials: N
authors.lastname: Liang
authors.forename: Xiaoqing
authors.initials: X
authors.lastname: Wu
mesh_terms: D000327:Adsorption; D002248:Carbon Monoxide / Q000032:analysis / Q000737:chemistry; D005740:Gases / Q000032:analysis*; D006862:Hydrogen Sulfide / Q000032:analysis / Q000737:chemistry; D008958:Models, Molecular; D036103:Nanotechnology / Q000295:instrumentation / Q000379:methods; D037742:Nanotubes, Carbon / Q000737:chemistry* / Q000648:ultrastructure; D010984:Platinum / Q000737:chemistry*; D013458:Sulfur Dioxide / Q000032:analysis / Q000737:chemistry
chemical_list: D005740:Gases; D037742:Nanotubes, Carbon; D013458:Sulfur Dioxide; D010984:Platinum; D002248:Carbon Monoxide; D006862:Hydrogen Sulfide