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Doll T, Fuenzalida VM, Schütte H, Gaßmann S, Velasco-Velez JJ, Köhler R, Kontschev A, Haas T, Ungethüm B, Walte A, Oberröhrmann J, Onken A, Philipp KM, Nguyen MH, Lenarz T, Hassel AW, Viöl W. Physical Trace Gas Identification with the Photo Electron Ionization Spectrometer (PEIS). SENSORS (BASEL, SWITZERLAND) 2024; 24:1256. [PMID: 38400413 PMCID: PMC10891694 DOI: 10.3390/s24041256] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/20/2023] [Revised: 02/03/2024] [Accepted: 02/08/2024] [Indexed: 02/25/2024]
Abstract
Chemosensor technology for trace gases in the air always aims to identify these compounds and then measure their concentrations. For identification, traceable methods are sparse and relate to large appliances such as mass spectrometers. We present a new method that uses the alternative traceable measurement of the ionization energies of trace gases in a way that can be miniaturized and energetically tuned. We investigate the achievable performance. Since tunable UV sources are not available for photoionization, we take a detour via impact ionization with electrons, which we generate using the photoelectric effect and bring to sharp, defined energies on a nanoscale in the air. Electron impact ionization is thus possible at air pressures of up to 900 hPa. The sensitivity of the process reaches 1 ppm and is equivalent to that of classic PID. With sharpened energy settings, substance identification is currently possible with an accuracy of 30 meV. We can largely explain the experimental observations with the known quantum mechanical models.
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Affiliation(s)
- Theodor Doll
- Biomaterial Engineering, ENT, Hannover Medical School, 30625 Hannover, Germany; (A.O.); (M.-H.N.); (T.L.)
| | - Victor M. Fuenzalida
- Laboratorio de Superficies y Nanomateriales, Departamento de Física, FCFM, Universidad de Chile, Av. Blanco Encalada 2008, Santiago de Chile 8370448, Chile;
| | - Helmut Schütte
- Department of Engineering, Jade University of Applied Sciences, 26389 Wilhelmshaven, Germany; (H.S.); (S.G.)
| | - Stefan Gaßmann
- Department of Engineering, Jade University of Applied Sciences, 26389 Wilhelmshaven, Germany; (H.S.); (S.G.)
| | | | - Robert Köhler
- Faculty of Engineering and Health, University of Applied Sciences and Arts, Von-Ossietzky-Straße 99, 37085 Göttingen, Germany; (R.K.); (W.V.)
| | | | - Thomas Haas
- Adlantis GmbH, 44263 Dortmund, Germany; (A.K.); (T.H.)
| | - Bert Ungethüm
- Airsense Analytics GmbH, 19061 Schwerin, Germany; (B.U.); (A.W.)
| | - Andreas Walte
- Airsense Analytics GmbH, 19061 Schwerin, Germany; (B.U.); (A.W.)
| | | | - Adrian Onken
- Biomaterial Engineering, ENT, Hannover Medical School, 30625 Hannover, Germany; (A.O.); (M.-H.N.); (T.L.)
| | | | - Minh-Hai Nguyen
- Biomaterial Engineering, ENT, Hannover Medical School, 30625 Hannover, Germany; (A.O.); (M.-H.N.); (T.L.)
| | - Thomas Lenarz
- Biomaterial Engineering, ENT, Hannover Medical School, 30625 Hannover, Germany; (A.O.); (M.-H.N.); (T.L.)
| | - Achim Walter Hassel
- Institute of Chemical Technology of Inorganic Materials, Johannes Kepler University Linz, 4040 Linz, Austria;
| | - Wolfgang Viöl
- Faculty of Engineering and Health, University of Applied Sciences and Arts, Von-Ossietzky-Straße 99, 37085 Göttingen, Germany; (R.K.); (W.V.)
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Chizhov A, Kutukov P, Gulin A, Astafiev A, Rumyantseva M. Highly Active Nanocrystalline ZnO and Its Photo-Oxidative Properties towards Acetone Vapor. MICROMACHINES 2023; 14:mi14050912. [PMID: 37241536 DOI: 10.3390/mi14050912] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/12/2023] [Revised: 04/14/2023] [Accepted: 04/18/2023] [Indexed: 05/28/2023]
Abstract
Zinc oxide is one of the well-known photocatalysts, the potential applications of which are of great importance in photoactivated gas sensing, water and air purification, photocatalytic synthesis, among others. However, the photocatalytic performance of ZnO strongly depends on its morphology, composition of impurities, defect structure, and other parameters. In this paper, we present a route for the synthesis of highly active nanocrystalline ZnO using commercial ZnO micropowder and ammonium bicarbonate as starting precursors in aqueous solutions under mild conditions. As an intermediate product, hydrozincite is formed with a unique morphology of nanoplates with a thickness of about 14-15 nm, the thermal decomposition of which leads to the formation of uniform ZnO nanocrystals with an average size of 10-16 nm. The synthesized highly active ZnO powder has a mesoporous structure with a BET surface area of 79.5 ± 4.0 m2/g, an average pore size of 20 ± 2 nm, and a cumulative pore volume of 0.507 ± 0.051 cm3/g. The defect-related PL of the synthesized ZnO is represented by a broad band with a maximum at 575 nm. The crystal structure, Raman spectra, morphology, atomic charge state, and optical and photoluminescence properties of the synthesized compounds are also discussed. The photo-oxidation of acetone vapor over ZnO is studied by in situ mass spectrometry at room temperature and UV irradiation (λmax = 365 nm). The main products of the acetone photo-oxidation reaction, water and carbon dioxide, are detected by mass spectrometry, and the kinetics of their release under irradiation are studied. The effect of morphology and microstructure on the photo-oxidative activity of ZnO samples is demonstrated.
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Affiliation(s)
- Artem Chizhov
- Chemistry Department, Moscow State University, Moscow 119991, Russia
| | - Pavel Kutukov
- Chemistry Department, Moscow State University, Moscow 119991, Russia
| | - Alexander Gulin
- N.N. Semenov Federal Research Center for Chemical Physics of Russian Academy of Sciences, Moscow 119991, Russia
| | - Artyom Astafiev
- N.N. Semenov Federal Research Center for Chemical Physics of Russian Academy of Sciences, Moscow 119991, Russia
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