Pd@SnO2 and SnO2@Pd Core@Shell Nanocomposite Sensors

Particle & Particle Systems Characterization,Volume 31, Issue 5, pages 591–596, 2014.

Fabian Gyger¹, André Sackmann², Michael Hübner², Pascal Bockstaller³, Dagmar Gerthsen³, Henning Lichtenberg⁴, Jan-Dierk Grunwaldt⁴, Nicolae Barsan^2*, Udo Weimar^2*, and Claus Feldmann^1*

^[1]    F. Gyger, Prof. Dr. C. Feldmann, Institut für Anorganische Chemie, Karlsruhe Institute of Technology (KIT) Engesserstraße 15, Karlsruhe, D-76131, Germany,

E-mail: [email protected]

^[2]   A: Sackmann, M: Hübner, Dr. N. Barsan, Prof. Dr. U. Weimar, Institut für Physikalische und Theoretische Chemie, Universität Tübingen
Auf der Morgenstelle 15, D-72076 Tübingen, Germany. E-mail: [email protected]

^[3]    P. Bockstaller, Prof. Dr. D. Gerthsen, Laboratorium für Elektronenmikroskopie, Karlsruhe Institute of Technology (KIT), Engesserstraße 7, D-76131 Karlsruhe, Germany

^[4]   H. Lichtenberg, Prof. Dr. J.-D. Grunwaldt, Institut für Technische Chemie und Polymerchemie,  Karlsruhe Institute of Technology (KIT),  Engesserstraße 20, D-76131 Karlsruhe, Germany.

 

Abstract.

Pd@SnO₂ and SnO₂@Pd core@shell nanocomposites are prepared via a microemulsion approach. Both nanocomposites exhibit high-surface, porous matrices of SnO₂ shells (>150 m²/g) with very small SnO₂ crystallites (<10 nm) and Pd nanoparticles (<10 nm) that are uniformly distributed in the porous SnO₂ matrix. Although similar by first sight, Pd@SnO₂ and SnO₂@Pd are significantly different in view of their structure with Pd inside or outside the SnO₂ shell and in view of their sensor performance. As SMOX-based sensors (SMOX: Semiconducting Metal Oxide) both nanocomposites show a very good sensor performance for the detection of CO and H₂. Especially, the Pd@SnO₂ core@shell nanocomposite is unique and shows a fast response time (τ₉₀ < 30 seconds) and a very good response at low temperature (<250 °C), especially under humid-air conditions. Extraordinarily high sensor signals are observed when exposing the Pd@SnO₂ nanocomposite to CO in humid air. Under these conditions even commercial sensors (Figaro TGS 2442, Applied Sensor MLC, E2V MICS 5521) are outperformed.

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