title: Metal-organic frameworks for sensing applications in the gas phase.
abstract: Several metal-organic framework (MOF) materials were under investigated to test their applicability as sensor materials for impedimetric gas sensors. The materials were tested in a temperature range of 120 °C - 240 °C with varying concentrations of O(2), CO(2), C(3)H(8), NO, H(2), ethanol and methanol in the gas atmosphere and under different test gas humidity conditions. Different sensor configurations were studied in a frequency range of 1 Hz -1 MHz and time-continuous measurements were performed at 1 Hz. The materials did not show any impedance response to O(2), CO(2), C(3)H(8), NO, or H(2) in the gas atmospheres, although for some materials a significant impedance decrease was induced by a change of the ethanol or methanol concentration in the gas phase. Moreover, pronounced promising and reversible changes in the electric properties of a special MOF material were monitored under varying humidity, with a linear response curve at 120 °C. Further investigations were carried out with differently doped MOF materials of this class, to evaluate the influence of special dopants on the sensor effect.
authors.affiliation: Functional Materials, University of Bayreuth, Universitätsstr. 30, 95440 Bayreuth, Germany.
authors.forename: Sabine
authors.initials: S
authors.lastname: Achmann
authors.forename: Gunter
authors.initials: G
authors.lastname: Hagen
authors.forename: Jaroslaw
authors.initials: J
authors.lastname: Kita
authors.forename: Itamar M
authors.initials: IM
authors.lastname: Malkowsky
authors.forename: Christoph
authors.initials: C
authors.lastname: Kiener
authors.forename: Ralf
authors.initials: R
authors.lastname: Moos