title: Gas sensing with Au-decorated carbon nanotubes.
abstract: The sensing properties of carbon nanotubes (CNTs) decorated with gold nanoparticles have been investigated by means of combined theoretical and experimental approaches. On one hand, first-principles and nonequilibrium Green's functions techniques give access to the microscopic features of the sensing mechanisms in individual nanotubes, such as electronic charge transfers and quantum conductances. On the other hand, drop coating deposition of carbon nanotubes decorated with gold nanoparticles onto sensor substrates and their characterization in the detection of pollutants such as NO(2), CO, and C(6)H(6) provide insight into the sensing ability of nanotube mats. Using the present combined approaches, the improvement in the detection of some specific gases (NO(2) and CO) using Au-functionalized nanotubes is explained. However, for other gases such as C(6)H(6), the Au nanoparticles do not seem to play a crucial role in the sensing process when compared with pristine CNTs functionalized with oxygen plasma. Indeed, these different situations can be explained by identifying the relationship between the change of resistance (macroscopic feature) and the shift of the Fermi level (microscopic feature) after gas adsorption. The understanding of the sensing ability at the atomic level opens the way to design new gas sensors and to tune their selectivity by predicting the nature of the metal that is the most appropriate to detect specific molecular species.
authors.affiliation: Institute of Condensed Matter and Nanosciences (IMCN), Université Catholique de Louvain, Place Croix du Sud 1 (NAPS-ETSF-Boltzmann), 1348 Louvain-la-Neuve, Belgium. zeilazanolli@gmail.com
authors.forename: Zeila
authors.initials: Z
authors.lastname: Zanolli
authors.forename: Radouane
authors.initials: R
authors.lastname: Leghrib
authors.forename: Alexandre
authors.initials: A
authors.lastname: Felten
authors.forename: Jean-Jacques
authors.initials: JJ
authors.lastname: Pireaux
authors.forename: Eduard
authors.initials: E
authors.lastname: Llobet
authors.forename: Jean-Christophe
authors.initials: JC
authors.lastname: Charlier
mesh_terms: D000327:Adsorption; D000393:Air Pollutants / Q000737:chemistry; D002244:Carbon / Q000737:chemistry; D002245:Carbon Dioxide / Q000737:chemistry; D005740:Gases; D006046:Gold / Q000737:chemistry*; D053768:Metal Nanoparticles / Q000737:chemistry; D008855:Microscopy, Electron, Scanning / Q000379:methods; D046529:Microscopy, Electron, Transmission / Q000379:methods; D036103:Nanotechnology / Q000379:methods*; D037742:Nanotubes, Carbon / Q000737:chemistry*; D010100:Oxygen / Q000737:chemistry; D011789:Quantum Theory; D013052:Spectrometry, X-Ray Emission / Q000379:methods; D013696:Temperature
chemical_list: D000393:Air Pollutants; D005740:Gases; D037742:Nanotubes, Carbon; D002245:Carbon Dioxide; D002244:Carbon; D006046:Gold; D010100:Oxygen