NO2 Detection by Pulsed Polarization of Doped Bismuth Vanadate films prepared by the Aerosol Deposition Method

Titelangaben

Exner, Jörg ; Albrecht, Gaby ; Fuierer, Paul ; Moos, Ralf:
NO2 Detection by Pulsed Polarization of Doped Bismuth Vanadate films prepared by the Aerosol Deposition Method.
2015
Veranstaltung: 7th International Conference on Electroceramics (ICE2015), State College , 13.05.-16.05.2015 , State College, Pennsylvania, USA.
(Veranstaltungsbeitrag: Kongress/Konferenz/Symposium/Tagung , Vortrag )

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Abstract

The pulse-polarization measurement technique using conventional YSZ substrates has recently shown a great potential to detect low concentrations of NOx in exhausts. Our objective is to replace the screen-printed YSZ thick film by a novel oxygen ion conducting solid electrolyte based on (Cu, Ti) substituted bismuth vanadate, which is prepared by the aerosol deposition method (ADM).

The sensor setup consisted of an alumina substrate, on which a dense Bi4(Cu0.05Ti0.05V0.9)2O10.8 (BiCuTiVOx) film with 5 μm thickness was applied by the room temperature impact consolidation (RTIC) of ceramic particles, or aerosol deposition [2]. Subsequently, screen printed and sintered Pt interdigital electrodes were applied on top of the film. The Pulse-polarization method is based on the self-discharge of the electrodes measured after applying alternating voltage pulses. These measurements were performed in a quartz tube furnace at 300, 350, and 400 °C. Gas concentrations inside the furnace were adjusted by mass flow controllers and consisted of a base gas (10 % O2, 2 vol.-% H2O in N2) with varying NO and NO2 concentrations (0, 3, 6, 12, 24 ppm).

In contrast to previous reported measurements with YSZ electrolytes, only additions of NO2 led to a different self-discharge compared to the base gas. Additions of NO did not. The sensor output ΔU was independent on the NO concentration and therefore highly selective to NO2. The highest sensitivity is obtained at 350 °C with SΔU = 3.5 mV/ppm(NO2), allowing the quantitative detection of NO2 in the low ppm range.