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Sensor performance of nanostructured TiO2-SnO2 films prepared by an Aqueous Sol-Gel process

Farahpour, P ; Sharif University of Technology

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  1. Type of Document: Article
  2. DOI: 10.1007/s10876-013-0672-2
  3. Abstract:
  4. Nanostructured TiO2-SnO2 thin films and powders were prepared by a facile aqueous particulate sol-gel route. The prepared sols showed a narrow particle size distribution with hydrodynamic diameter in the range 17.2-19.3 nm. Moreover, the sols were stable over 5 months, since the constant zeta potential was measured during this period. The effect of Sn:Ti molar ratio was studied on the crystallisation behaviour of the products. X-ray diffraction analysis revealed that the powders were crystallised at the low temperature of 400 °C containing anatase-TiO2, rutile-TiO2 and cassiterite-SnO2 phases, depending on annealing temperature and Sn:Ti molar ratio. Furthermore, it was found that SnO2 retarded the anatase to rutile transformation up to 800 °C. The activation energy of crystallite growth was calculated in the range 0.96-6.87 kJ/mol. Transmission electron microscope image showed that one of the smallest crystallite sizes was obtained for TiO2-SnO2 binary mixed oxide, being 3 nm at 600 °C. Field emission scanning electron microscope analysis revealed that the deposited thin films had nanostructured morphology with the average grain size in the range 20-40 nm at 600 °C. Thin films produced under optimized conditions showed excellent microstructural properties for gas sensing applications. They exhibited a remarkable response towards low concentrations of CO gas at low operating temperature of 200 °C, resulting in increased thermal stability of sensing films as well as a decrease in their power consumption
  5. Keywords:
  6. TiO2–SnO2 ; Aqueous particulate sol–gel ; Nanostructured ; Sn:Ti molar ratio
  7. Source: Journal of Cluster Science ; Volume 25, Issue 4 , July 2014 , Pages 905-923
  8. URL: http://link.springer.com/article/10.1007%2Fs10876-013-0672-2