p-CoO_{x}In-SnO_{2}$ nanostructures : new highly selective materials for H_{2}S$ detection
| Autor: | N. O. Khmelevsky, Marina Rumyantseva, Irina Giebelhaus, A. Yu. Aksenenko, Artem M. Abakumov, Olesia M. Karakulina, Joke Hadermann, V.F. Kozlovsky, Sanjay Mathur, S.A. Vladimirova, Alexander Gaskov, N. A. Vorobyeva, A.S. Chizhov |
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| Jazyk: | angličtina |
| Rok vydání: | 2018 |
| Předmět: |
inorganic chemicals
Materials science Nanowire chemistry.chemical_element Nanoparticle Nanotechnology 02 engineering and technology 010402 general chemistry 01 natural sciences chemistry.chemical_compound X-ray photoelectron spectroscopy Materials Chemistry Electrical and Electronic Engineering Instrumentation Cobalt oxide Physics Metals and Alloys 021001 nanoscience & nanotechnology Condensed Matter Physics Tin oxide equipment and supplies Cobalt sulfide 0104 chemical sciences Surfaces Coatings and Films Electronic Optical and Magnetic Materials Chemistry chemistry Chemical engineering 0210 nano-technology Selectivity Cobalt |
| Zdroj: | Sensors and actuators : B : chemical |
| ISSN: | 0925-4005 |
| Popis: | Nanostructures p-CoOx/n-SnO2 based on tin oxide nanowires have been prepared by two step CVD technique and characterized in detail by XRD, XRF, XPS, HAADF-STEM imaging and EDX-STEM mapping. Depending on the temperature of decomposition of cobalt complex during the second step of CVD synthesis of nanostructures cobalt oxide forms a coating and/or isolated nanoparticles on SnO2 nanowire surface. It was found that cobalt presents in +2 and +3 oxidation states. The measurements of gas sensor properties have been carried out during exposure to CO (14 ppm), NH3 (21 ppm), and H2S (2 ppm) in dry air. The opposite trends were observed in the effect of cobalt oxide on the SnO2 gas sensitivity when detecting CO or NH3 in comparison to H2S. The decrease of sensor signal toward CO and NH3 was attributed to high catalytic activity of Co3O4 in oxidation of these gases. Contrary, the significant increase of sensor signal in the presence of H2S was attributed to the formation of metallic cobalt sulfide and removal of the barrier between p-CoOx and n-SnO2. This effect provides an excellent selectivity of p-CoOx/n-SnO2 nanostructures in H2S detection. |
| Databáze: | OpenAIRE |
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