SnO2 thin-films prepared by a spray-gel pyrolysis: Influence of sol properties on film morphologies

Nanostructured tin oxide films were prepared by depositing different sols using the so-called spray-gel pyrolysis process. SnO2 suspensions (sols) were obtained from tin (IV) tert-amyloxide (Sn(t-OAm)4) or tin (IV) chloride pentahydrate (SnCl4·5H2O) precursors, and stabilized with ammonia or tetraet...

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Autores principales: Fábregas, Ismael Oscar, Candal, Roberto Jorge
Publicado: 2007
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Acceso en línea:https://bibliotecadigital.exactas.uba.ar/collection/paper/document/paper_00406090_v516_n1_p25_Luyo
http://hdl.handle.net/20.500.12110/paper_00406090_v516_n1_p25_Luyo
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spelling paper:paper_00406090_v516_n1_p25_Luyo2023-06-08T15:04:37Z SnO2 thin-films prepared by a spray-gel pyrolysis: Influence of sol properties on film morphologies Fábregas, Ismael Oscar Candal, Roberto Jorge Gas sensor Spray-gel Thin film Tin dioxide Chemical sensors Morphology Pyrolysis Sol-gel process Tin oxides Xerogels Relative Gelling Volumes (RGV) Spray-gel Tert-amyloxide Tetraethylammonium hydroxide (TEA-OH) Thin films Nanostructured tin oxide films were prepared by depositing different sols using the so-called spray-gel pyrolysis process. SnO2 suspensions (sols) were obtained from tin (IV) tert-amyloxide (Sn(t-OAm)4) or tin (IV) chloride pentahydrate (SnCl4·5H2O) precursors, and stabilized with ammonia or tetraethylammonium hydroxide (TEA-OH). Xerogels from the different sols were obtained by solvent evaporation under controlled humidity. The Relative Gelling Volumes (RGV) of these sols strongly depended on the type of precursor. Xerogels obtained from inorganic salts gelled faster, while, as determined by thermal gravimetric analysis, occluding a significant amount of volatile compounds. Infrared spectroscopic analysis was performed on raw and annealed xerogels (300, 500 °C, 1 h). Annealing removed water and ammonium or alkyl ammonium chloride, increasing the number of Sn-O-Sn bonds. SnO2 films were prepared by spraying the sols for 60 min onto glass and alumina substrates at 130 °C. The films obtained from all the sols were amorphous or displayed a very small grain size, and crystallized after annealing at 400 °C or 500 °C in air for 2 h. X-ray diffraction analysis showed the presence of the cassiterite structure and line broadening indicated a polycrystalline material with a grain size in the nanometer range. Results obtained from Scanning Electron Microscopy analysis demonstrated a strong dependence of the film morphology on the RGV of the sols. Films obtained from Sn(t-OAm)4 showed a highly textured morphology based on fiber-shape bridges, whereas the films obtained from SnCl4·5H2O had a smoother surface formed by "O-ring" shaped domains. Lastly, the performance of these films as gas sensor devices was tested. The conductance (sensor) response for ethanol as a target analyte was of the same order of magnitude for the three kinds of films. However, the response of the highly textured films was more stable with shorter response times. © 2007 Elsevier B.V. All rights reserved. Fil:Fábregas, I. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales; Argentina. Fil:Candal, R.J. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales; Argentina. 2007 https://bibliotecadigital.exactas.uba.ar/collection/paper/document/paper_00406090_v516_n1_p25_Luyo http://hdl.handle.net/20.500.12110/paper_00406090_v516_n1_p25_Luyo
institution Universidad de Buenos Aires
institution_str I-28
repository_str R-134
collection Biblioteca Digital - Facultad de Ciencias Exactas y Naturales (UBA)
topic Gas sensor
Spray-gel
Thin film
Tin dioxide
Chemical sensors
Morphology
Pyrolysis
Sol-gel process
Tin oxides
Xerogels
Relative Gelling Volumes (RGV)
Spray-gel
Tert-amyloxide
Tetraethylammonium hydroxide (TEA-OH)
Thin films
spellingShingle Gas sensor
Spray-gel
Thin film
Tin dioxide
Chemical sensors
Morphology
Pyrolysis
Sol-gel process
Tin oxides
Xerogels
Relative Gelling Volumes (RGV)
Spray-gel
Tert-amyloxide
Tetraethylammonium hydroxide (TEA-OH)
Thin films
Fábregas, Ismael Oscar
Candal, Roberto Jorge
SnO2 thin-films prepared by a spray-gel pyrolysis: Influence of sol properties on film morphologies
topic_facet Gas sensor
Spray-gel
Thin film
Tin dioxide
Chemical sensors
Morphology
Pyrolysis
Sol-gel process
Tin oxides
Xerogels
Relative Gelling Volumes (RGV)
Spray-gel
Tert-amyloxide
Tetraethylammonium hydroxide (TEA-OH)
Thin films
description Nanostructured tin oxide films were prepared by depositing different sols using the so-called spray-gel pyrolysis process. SnO2 suspensions (sols) were obtained from tin (IV) tert-amyloxide (Sn(t-OAm)4) or tin (IV) chloride pentahydrate (SnCl4·5H2O) precursors, and stabilized with ammonia or tetraethylammonium hydroxide (TEA-OH). Xerogels from the different sols were obtained by solvent evaporation under controlled humidity. The Relative Gelling Volumes (RGV) of these sols strongly depended on the type of precursor. Xerogels obtained from inorganic salts gelled faster, while, as determined by thermal gravimetric analysis, occluding a significant amount of volatile compounds. Infrared spectroscopic analysis was performed on raw and annealed xerogels (300, 500 °C, 1 h). Annealing removed water and ammonium or alkyl ammonium chloride, increasing the number of Sn-O-Sn bonds. SnO2 films were prepared by spraying the sols for 60 min onto glass and alumina substrates at 130 °C. The films obtained from all the sols were amorphous or displayed a very small grain size, and crystallized after annealing at 400 °C or 500 °C in air for 2 h. X-ray diffraction analysis showed the presence of the cassiterite structure and line broadening indicated a polycrystalline material with a grain size in the nanometer range. Results obtained from Scanning Electron Microscopy analysis demonstrated a strong dependence of the film morphology on the RGV of the sols. Films obtained from Sn(t-OAm)4 showed a highly textured morphology based on fiber-shape bridges, whereas the films obtained from SnCl4·5H2O had a smoother surface formed by "O-ring" shaped domains. Lastly, the performance of these films as gas sensor devices was tested. The conductance (sensor) response for ethanol as a target analyte was of the same order of magnitude for the three kinds of films. However, the response of the highly textured films was more stable with shorter response times. © 2007 Elsevier B.V. All rights reserved.
author Fábregas, Ismael Oscar
Candal, Roberto Jorge
author_facet Fábregas, Ismael Oscar
Candal, Roberto Jorge
author_sort Fábregas, Ismael Oscar
title SnO2 thin-films prepared by a spray-gel pyrolysis: Influence of sol properties on film morphologies
title_short SnO2 thin-films prepared by a spray-gel pyrolysis: Influence of sol properties on film morphologies
title_full SnO2 thin-films prepared by a spray-gel pyrolysis: Influence of sol properties on film morphologies
title_fullStr SnO2 thin-films prepared by a spray-gel pyrolysis: Influence of sol properties on film morphologies
title_full_unstemmed SnO2 thin-films prepared by a spray-gel pyrolysis: Influence of sol properties on film morphologies
title_sort sno2 thin-films prepared by a spray-gel pyrolysis: influence of sol properties on film morphologies
publishDate 2007
url https://bibliotecadigital.exactas.uba.ar/collection/paper/document/paper_00406090_v516_n1_p25_Luyo
http://hdl.handle.net/20.500.12110/paper_00406090_v516_n1_p25_Luyo
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AT candalrobertojorge sno2thinfilmspreparedbyaspraygelpyrolysisinfluenceofsolpropertiesonfilmmorphologies
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