title: Recognizing Physisorption and Chemisorption in Carbon Nanotubes Gas Sensors by Double Exponential Fitting of the Response.
abstract: Multi-walled carbon nanotubes (CNTs) have been grown in situ on a SiO 2 substrate and used as gas sensors. For this purpose, the voltage response of the CNTs as a function of time has been used to detect H 2 and CO 2 at various concentrations by supplying a constant current to the system. The analysis of both adsorptions and desorptions curves has revealed two different exponential behaviours for each curve. The study of the characteristic times, obtained from the fitting of the data, has allowed us to identify separately chemisorption and physisorption processes on the CNTs.
authors.affiliation: Department of Physics, University of Trieste, via A. Valerio 2, 34127 Trieste, Italy. andrea.calvi@studenti.units.it.
authors.forename: Andrea
authors.initials: A
authors.lastname: Calvi
authors.affiliation: Department of Physics, University of Trieste, via A. Valerio 2, 34127 Trieste, Italy. alberto.ferrari@studenti.units.it.
authors.forename: Alberto
authors.initials: A
authors.lastname: Ferrari
authors.affiliation: Department of Physics, University of Trieste, via A. Valerio 2, 34127 Trieste, Italy. luca.sbuelz@studenti.units.it.
authors.forename: Luca
authors.initials: L
authors.lastname: Sbuelz
authors.affiliation: Elettra-Sincrotrone Trieste, S.S. 14, km 163.5, 34149 Trieste, Italy. andrea.goldoni@elettra.eu.
authors.forename: Andrea
authors.initials: A
authors.lastname: Goldoni
authors.affiliation: Department of Physics, University of Trieste, via A. Valerio 2, 34127 Trieste, Italy. Silvio.Modesti@ts.infn.it.|CNR-IOM TASC, S.S. 14, km 163.5, 34149 Trieste, Italy. Silvio.Modesti@ts.infn.it.
authors.forename: Silvio
authors.initials: S
authors.lastname: Modesti
keywords: CNTs sensors; chemisorption; physisorption