Correlation between XPS, Raman and TEM measurements and the gas sensitivity of Pt and Pd doped SnO 2 based gas sensors

Kappler, J. P.; Bârsan, Nicolae; Weimar, Udo; Diéguez, Ángel; Alay, Josep Lluís; Romano‐Rodríguez, A.; Morante, J.R.; Göpel, Wolfgang

doi:10.1007/s002160050844

Cited by 116 publications

(56 citation statements)

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“…They also reported that the Pt was reduced to the metallic state in a reducing gas and the redox of Pt was related to its sensing properties. Other works by Lee 33 and Kappler 34 showed the presence of both oxidized and metallic Pt states and the active site structure was not clarified. Weimer et al claimed Pt atomically dispersed in the SnO 2 lattice was active structure which generated atom/molecular adsorption sites for oxygen near the Pt atoms at the surface.…”

Section: Structure and Activitymentioning

confidence: 93%

Characterization of Pt-doped SnO2 catalyst for a high-performance micro gas sensor

Murata

Suzuki

Kobayashi

et al. 2013

Phys. Chem. Chem. Phys.

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The atomic scale structure and its dependence on Pt concentration of a Pt-doped SnO 2 (Pt/SnO 2 ) thin film produced by a sputter-deposition method was investigated，which showed a high-performance methane gas sensor. Extended X-ray absorption fine structure (EXAFS) and X-ray diffraction (XRD) analyses showed that Pt/SnO 2 has a rutile structure similar to SnO 2 crystals at less than 10 at% Pt where the Pt ion was located at the Sn position in the rutile structure. There was no evidence that Pt metal clusters were formed in the Pt/SnO 2 films. The Pt/SnO 2 structure became amorphous at greater than 11 at% Pt. We found a good correlation between the methane activity and local structure of Pt.

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Section: Structure and Activitymentioning

confidence: 93%

Characterization of Pt-doped SnO2 catalyst for a high-performance micro gas sensor

Murata

Suzuki

Kobayashi

et al. 2013

Phys. Chem. Chem. Phys.

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“…Those two specific sensors' annealing temperatures have been chosen because it was shown that a temperature of at least 450 8C is needed to start the process of desorption of surface lattice oxygen [18] while at temperatures higher than 600 8C, desorption of bulk lattice oxygen becomes possible [24]. Kappler et al [25,26] observed that annealing of the sensors do not influence the morphology (grain size, porosity, etc.). Our gain in this case is clear-by having a fixed morphology, the microstructure of tin dioxide based sensors is changed in a controlled way.…”

Section: Methodsmentioning

confidence: 99%

Influence of annealing temperature on the CO sensing mechanism for tin dioxide based sensors–Operando studies

et al. 2007

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“…Our observations suggest a core-shell structure for the nanocomposite SnO 2 / PtO 2 in which platinum dioxide lies at the surface of tin dioxide particles through an interface constituted of SnO 2 -bonded Pt species and rule out the presence of metallic platinum at the surface of tin oxide grains, in agreement with previous observations. 52 XAS studies of the fully oxidized Pd-doped Sn/SnO x nanoparticles XANES spectra of the Pd doped nanomaterial as-prepared and after its full oxidation along with pure PdO and bulk Pd metal references are presented in Fig. 8.…”

Section: Synthesis and Characterization Of [Sn/sno X /Pt] Nanoparticlesmentioning

confidence: 99%

Organometallic approach for platinum and palladium doping of tin and tin oxide nanoparticles: structural characterisation and gas sensor investigations

et al. 2006

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Platinum and palladium surface doped tin nanoparticles have been obtained by decomposition of [Pt 2 (dba) 3 ] and [Pd(dba) 2 ] organometallic precursors, respectively, in a colloidal suspension of tin/ tin oxide core-shell nanoparticles of uniform size (E13 nm), in anisole under 1 bar of carbon monoxide at room temperature. The particles can be isolated as pure solids and present effective doping ratios [Pt]/[Sn] and [Pd]/[Sn] of 2.5 and 3.1%, respectively. These nanomaterials have been characterized by means of transmission electron and high-resolution transmission electron microscopies (TEM and HRTEM), Energy Dispersive X-ray spectroscopy (EDX), photoelectron spectroscopy (XPS) and X-ray absorption spectroscopy (EXAFS and XANES). The TEM micrographs show spherical nanoparticles whose size and size distribution are essentially similar to those of the initial Sn/SnO x material. HRTEM, EDX, XPS and X-ray absorption spectroscopy (XAS) studies at the Pd and/or Sn-K edge show the conservation of the composite nature of the particles that consist of a tin(0) core covered with a layer of tin oxides on which the doping element is deposited under the form of crystalline metallic platelets of size near 2 nm. The thermal oxidation of these Pt-or Pd-doped tin materials yields nanoparticles of crystallized SnO 2 covered with crystallites of Pt or Pd oxides, as demonstrated by XRD, XPS and XAS experiments, without coalescence or size change. In the oxidised Pd-doped material, EXAFS analysis combined with HRTEM, point towards the formation of two main Pd disordered oxide phases: a rather pure oxopalladate Pd 3.5 O 4 -type phase at the surface of the particle and a mixed Pd/Sn phase having a PdO structure-type at the interface Pd oxide/Sn oxide. The thermal oxidation process can be easily achieved onto the silicon platform of a micro-machined device after integration of the Pt-or Pd-doped Sn/SnO x colloidal suspension by drop deposition. The first electrical measurements indicate remarkable behaviours of the as-obtained microsensors when exposed to traces of carbon monoxide. In addition to the expected large increase of sensitivity of the doped relatively to the undoped sensitive layer measured in humid atmosphere, a surprising and unprecedented inversion of sensitivity from undoped to Pt-and Pd-doped sensors has been observed in dry atmosphere.

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Correlation between XPS, Raman and TEM measurements and the gas sensitivity of Pt and Pd doped SnO 2 based gas sensors

Cited by 116 publications

References 1 publication

Characterization of Pt-doped SnO2 catalyst for a high-performance micro gas sensor

Characterization of Pt-doped SnO2 catalyst for a high-performance micro gas sensor

Influence of annealing temperature on the CO sensing mechanism for tin dioxide based sensors–Operando studies

Organometallic approach for platinum and palladium doping of tin and tin oxide nanoparticles: structural characterisation and gas sensor investigations

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