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Influence of Thickness on Ethanol Sensing Characteristics of Doctor-bladed Thick Film from Flame-made ZnO Nanoparticles

View Article: PubMed Central

ABSTRACT

ZnO nanoparticles were produced by flame spray pyrolysis (FSP) using zinc naphthenate as a precursor dissolved in toluene/acetonitrile (80/20 vol%). The particle properties were analyzed by XRD, BET, and HR-TEM. The sensing films were produced by mixing the particles into an organic paste composed of terpineol and ethyl cellulose as a vehicle binder and were fabricated by doctor-blade technique with various thicknesses (5, 10, 15 μm). The morphology of the sensing films was analyzed by SEM and EDS analyses. The gas sensing characteristics to ethanol (25-250 ppm) were evaluated as a function of film thickness at 400°C in dry air. The relationship between thickness and ethanol sensing characteristics of ZnO thick film on Al2O3 substrate interdigitated with Au electrodes were investigated. The effects of film thickness, as well as the cracking phenomenon, though, many cracks were observed for thicker sensing films. Crack widths increased with increasing film thickness. The film thickness, cracking and ethanol concentration have significant effect on the sensing characteristics. The sensing characteristics with various thicknesses were compared, showing the tendency of the sensitivity to ethanol decreased with increasing film thickness and response time. The relationship between gas sensing properties and film thickness was discussed on the basis of diffusively and reactivity of the gases inside the oxide films. The thinnest sensing film (5 μm) showed the highest sensitivity and the fastest response time (within seconds).

No MeSH data available.


TEM bright-fields image of highly crystalline flame-made (5/5) ZnO nanoparticles at: (a) low and (b) high magnifications. The morphologies can be observed (b) mainly spheroidal particles typically with occasional hexagonal and rod-like particles. Insets (a) show the corresponding diffraction patterns of the particles.
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f5-sensors-07-00185: TEM bright-fields image of highly crystalline flame-made (5/5) ZnO nanoparticles at: (a) low and (b) high magnifications. The morphologies can be observed (b) mainly spheroidal particles typically with occasional hexagonal and rod-like particles. Insets (a) show the corresponding diffraction patterns of the particles.

Mentions: Fig. 5 (a, b) show bright-field TEM images of samples P0 were observed at the different magnifications. The corresponding diffraction patterns are shown in the insets. The diffraction patterns illustrating spot patterns of the hexagonal structure of ZnO, indicated that the ZnO nanoparticles are highly crystalline, which is in good agreement with the XRD data. The flame made ZnO nanoparticles can be observed as particles having the clear rod-like, hexagonal, and spheroidal shape. Fig. 5 (b) shows the morphologies of flame made (5/5) ZnO nanoparticle contains mainly spheroidal particles typically with diameters ranging from 10-20 nm with occasional hexagonal and rod-like particles. The crystalline sizes of ZnO hexagonal particles were in the range of 10-20 nm, and nanorod-like particles were in the range of 10-20 nm in width, 20-50 nm in length. The morphology can be clearly seen the ZnO nanorods particles as shown in Fig. 6 (b). This is consistent with Tani et al. [25] and Height et al. [26, 27].


Influence of Thickness on Ethanol Sensing Characteristics of Doctor-bladed Thick Film from Flame-made ZnO Nanoparticles
TEM bright-fields image of highly crystalline flame-made (5/5) ZnO nanoparticles at: (a) low and (b) high magnifications. The morphologies can be observed (b) mainly spheroidal particles typically with occasional hexagonal and rod-like particles. Insets (a) show the corresponding diffraction patterns of the particles.
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Related In: Results  -  Collection

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getmorefigures.php?uid=PMC3756700&req=5

f5-sensors-07-00185: TEM bright-fields image of highly crystalline flame-made (5/5) ZnO nanoparticles at: (a) low and (b) high magnifications. The morphologies can be observed (b) mainly spheroidal particles typically with occasional hexagonal and rod-like particles. Insets (a) show the corresponding diffraction patterns of the particles.
Mentions: Fig. 5 (a, b) show bright-field TEM images of samples P0 were observed at the different magnifications. The corresponding diffraction patterns are shown in the insets. The diffraction patterns illustrating spot patterns of the hexagonal structure of ZnO, indicated that the ZnO nanoparticles are highly crystalline, which is in good agreement with the XRD data. The flame made ZnO nanoparticles can be observed as particles having the clear rod-like, hexagonal, and spheroidal shape. Fig. 5 (b) shows the morphologies of flame made (5/5) ZnO nanoparticle contains mainly spheroidal particles typically with diameters ranging from 10-20 nm with occasional hexagonal and rod-like particles. The crystalline sizes of ZnO hexagonal particles were in the range of 10-20 nm, and nanorod-like particles were in the range of 10-20 nm in width, 20-50 nm in length. The morphology can be clearly seen the ZnO nanorods particles as shown in Fig. 6 (b). This is consistent with Tani et al. [25] and Height et al. [26, 27].

View Article: PubMed Central

ABSTRACT

ZnO nanoparticles were produced by flame spray pyrolysis (FSP) using zinc naphthenate as a precursor dissolved in toluene/acetonitrile (80/20 vol%). The particle properties were analyzed by XRD, BET, and HR-TEM. The sensing films were produced by mixing the particles into an organic paste composed of terpineol and ethyl cellulose as a vehicle binder and were fabricated by doctor-blade technique with various thicknesses (5, 10, 15 μm). The morphology of the sensing films was analyzed by SEM and EDS analyses. The gas sensing characteristics to ethanol (25-250 ppm) were evaluated as a function of film thickness at 400°C in dry air. The relationship between thickness and ethanol sensing characteristics of ZnO thick film on Al2O3 substrate interdigitated with Au electrodes were investigated. The effects of film thickness, as well as the cracking phenomenon, though, many cracks were observed for thicker sensing films. Crack widths increased with increasing film thickness. The film thickness, cracking and ethanol concentration have significant effect on the sensing characteristics. The sensing characteristics with various thicknesses were compared, showing the tendency of the sensitivity to ethanol decreased with increasing film thickness and response time. The relationship between gas sensing properties and film thickness was discussed on the basis of diffusively and reactivity of the gases inside the oxide films. The thinnest sensing film (5 μm) showed the highest sensitivity and the fastest response time (within seconds).

No MeSH data available.