Beobachtung von Gassensoren während des Betriebs: Operando‐Raman‐FTIR‐Studie zur Ethanol‐Detektion durch Indiumoxid

Sänze, Sandra; Gurlo, Aleksander; Heß, Christian

doi:10.1002/ange.201207258

Cited by 3 publications

(1 citation statement)

References 15 publications

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“…In order to overcome this limitation, studies at in operando conditions were performed using multi-sensor arrangements [13]. In addition to X-ray methods [14], optical methods such as UV/Vis spectroscopy [15], Raman spectroscopy [16], and diffuse reflectance infrared (DRIFT) spectroscopy [17,18] were used to potentially detect the present surface species. Also, FTIR spectroscopy was combined with surface sensing techniques to investigate the oxidation of the analyte in the gas phase [19].…”

Section: Mox-measurement For Real-time Quantification Of Organic Compounds (Ch 4 )mentioning

confidence: 99%

Characterization of metal oxide gas sensors via optical techniques

et al. 2020

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Metal oxide (MOX) sensors are increasingly gaining attention in analytical applications. Their fundamental operation principle is based on conversion reactions of selected molecular species at their semiconducting surface. However, the exact turnover of analyte gas in relation to the concentration has not been investigated in detail to date. In the present study, two optical sensing techniques—luminescence quenching for molecular oxygen and infrared spectroscopy for carbon dioxide and methane—have been coupled for characterizing the behavior of an example semiconducting MOX methane gas sensor integrated into a recently developed low-volume gas cell. Thereby, oxygen consumption during MOX operation as well as the generation of carbon dioxide from the methane conversion reaction could be quantitatively monitored. The latter was analyzed via a direct mid-infrared gas sensor system based on substrate-integrated hollow waveguide (iHWG) technology combined with a portable Fourier transform infrared spectrometer, which has been able to not only detect the amount of generated carbon dioxide but also the consumption of methane during MOX operation. Hence, a method based entirely on direct optical detection schemes was developed for characterizing the actual signal generating processes—here for the detection of methane—via MOX sensing devices via near real-time online analysis.

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Section: Mox-measurement For Real-time Quantification Of Organic Compounds (Ch 4 )mentioning

confidence: 99%

Characterization of metal oxide gas sensors via optical techniques

et al. 2020

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Aufklärung des Mechanismus von SnO₂‐Gassensoren unter Betriebsbedingungen mittels kombinierter operando‐UV‐Vis‐, Raman‐ und IR‐Spektroskopie

Elger

Heß

2019

Angewandte Chemie

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SnO 2 ist das am häufigsten verwendete Material für Metalloxid-Gassensoren, aber ein detailliertes Verständnis der Funktionsweise steht trotz der Relevanz noch immer aus. Um mechanistische Einblicke in SnO 2-Gassensoren unter Arbeitsbedingungen zu erhalten, haben wir einen operando-Zugang entwickelt, der UV-Vis-, Raman-und FT-IR-Spektroskopie kombiniert, und es erstmals erlaubt, die Sensorantwort mit der Sauerstoffleerstellen-Konzentration im Metalloxid, der Art der Adsorbate und der Gasphasenzusammensetzung zu verknüpfen. Wir zeigen anhand der Ethanol-Gassensorik, dass der Sensorwiderstand direkt mit der Anzahl an Sauerstoffleerstellen an der Oberfläche und der Art der Oberflächenspezies, insbesondere der Acetat-und Hydroxyspezies, korreliert ist. Unsere operando-Ergebnisse erlauben eine Beurteilung der in der Literatur vorgeschlagenen Modelle hinsichtlich der Arbeitsweise von Gassensoren. Aufgrund ihres fundamentalen Charakters sind sie auch für andere Metalloxid-Gassensoren von unmittelbarer Relevanz.

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Elucidating the Mechanism of Working SnO₂ Gas Sensors Using Combined Operando UV/Vis, Raman, and IR Spectroscopy

Elger

Heß

2019

Angew Chem Int Ed

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SnO 2 is the most widely used metal oxide gas-sensing material but a detailed understanding of its functioning is still lacking despite its relevance for applications. To gain new mechanistic insight into SnO 2 gas sensors under working conditions, we have developed an operando approach based on combined UV/Vis, Raman, and FTIR spectroscopy, allowing us for the first time to relate the sensor response to the concentration of oxygen vacancies in the metal oxide, the nature of the adsorbates, and the gas-phase composition. We demonstrate with the example of ethanol gas sensing that the sensor resistance is directly correlated with the number of surface oxygen vacancies and the presence of surface species, in particular, acetate and hydroxy groups. Our operando results enable an assessment of mechanistic models proposed in the literature to explain gas sensor operation. Owing to their fundamental nature, our findings are of direct relevance also for other metal oxide gas sensors.

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Beobachtung von Gassensoren während des Betriebs: Operando‐Raman‐FTIR‐Studie zur Ethanol‐Detektion durch Indiumoxid

Cited by 3 publications

References 15 publications

Characterization of metal oxide gas sensors via optical techniques

Characterization of metal oxide gas sensors via optical techniques

Aufklärung des Mechanismus von SnO₂‐Gassensoren unter Betriebsbedingungen mittels kombinierter operando‐UV‐Vis‐, Raman‐ und IR‐Spektroskopie

Elucidating the Mechanism of Working SnO₂ Gas Sensors Using Combined Operando UV/Vis, Raman, and IR Spectroscopy

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Beobachtung von Gassensoren während des Betriebs: Operando‐Raman‐FTIR‐Studie zur Ethanol‐Detektion durch Indiumoxid

Cited by 3 publications

References 15 publications

Characterization of metal oxide gas sensors via optical techniques

Characterization of metal oxide gas sensors via optical techniques

Aufklärung des Mechanismus von SnO2‐Gassensoren unter Betriebsbedingungen mittels kombinierter operando‐UV‐Vis‐, Raman‐ und IR‐Spektroskopie

Elucidating the Mechanism of Working SnO2 Gas Sensors Using Combined Operando UV/Vis, Raman, and IR Spectroscopy

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Product

Resources

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Aufklärung des Mechanismus von SnO₂‐Gassensoren unter Betriebsbedingungen mittels kombinierter operando‐UV‐Vis‐, Raman‐ und IR‐Spektroskopie

Elucidating the Mechanism of Working SnO₂ Gas Sensors Using Combined Operando UV/Vis, Raman, and IR Spectroscopy