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Investigation of the carbon monoxide gas sensing characteristics of tin oxide mixed cerium oxide thin films.

Durrani SM, Al-Kuhaili MF, Bakhtiari IA, Haider MB - Sensors (Basel) (2012)

Bottom Line: The films were investigated for the detection of carbon monoxide, and were found to be highly sensitive.We found that 430 °C was the optimum operating temperature for sensing CO gas at concentrations as low as 5 ppm.Our sensors exhibited fast response and recovery times of 26 s and 30 s, respectively.

View Article: PubMed Central - PubMed

Affiliation: Physics Department, King Fahd University of Petroleum and Minerals, Dhahran 31261, Saudi Arabia. smayub@kfupm.edu.sa

ABSTRACT
Thin films of tin oxide mixed cerium oxide were grown on unheated substrates by physical vapor deposition. The films were annealed in air at 500 °C for two hours, and were characterized using X-ray photoelectron spectroscopy, atomic force microscopy and optical spectrophotometry. X-ray photoelectron spectroscopy and atomic force microscopy results reveal that the films were highly porous and porosity of our films was found to be in the range of 11.6-21.7%. The films were investigated for the detection of carbon monoxide, and were found to be highly sensitive. We found that 430 °C was the optimum operating temperature for sensing CO gas at concentrations as low as 5 ppm. Our sensors exhibited fast response and recovery times of 26 s and 30 s, respectively.

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High resolution XPS spectra of the deposited films: (a) Ce 3d region: the assignment of the peaks to the two sublevels of Ce 3d is shown, (b) Sn 3d region, (c) O 1s region: the spectrum is deconvoluted into three components and the experimental spectrum is represented by the circles.
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f3-sensors-12-02598: High resolution XPS spectra of the deposited films: (a) Ce 3d region: the assignment of the peaks to the two sublevels of Ce 3d is shown, (b) Sn 3d region, (c) O 1s region: the spectrum is deconvoluted into three components and the experimental spectrum is represented by the circles.

Mentions: Detailed spectra in the Ce 3d, Sn 3d, and O 1s core level regions are shown in Figure 3. CeO2 has a relatively complex Ce 3d XPS spectrum that consists of six peaks, which correspond to the three pairs of spin-orbit doublets of oxidized CeO2 [13]. The measured Ce 3d spectrum (Figure 3(a)) clearly shows five peaks at binding energies of 882.4 eV, 888.1 eV, 897.8 eV, 900.4 eV, and 906.7 eV. The first three peaks correspond to Ce 3d5/2 and the last two peaks correspond to Ce 3d3/2. An additional peak at a binding energy of 916.6 eV was observed in the survey scan (shown by the arrow in Figure 2).


Investigation of the carbon monoxide gas sensing characteristics of tin oxide mixed cerium oxide thin films.

Durrani SM, Al-Kuhaili MF, Bakhtiari IA, Haider MB - Sensors (Basel) (2012)

High resolution XPS spectra of the deposited films: (a) Ce 3d region: the assignment of the peaks to the two sublevels of Ce 3d is shown, (b) Sn 3d region, (c) O 1s region: the spectrum is deconvoluted into three components and the experimental spectrum is represented by the circles.
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC3376601&req=5

f3-sensors-12-02598: High resolution XPS spectra of the deposited films: (a) Ce 3d region: the assignment of the peaks to the two sublevels of Ce 3d is shown, (b) Sn 3d region, (c) O 1s region: the spectrum is deconvoluted into three components and the experimental spectrum is represented by the circles.
Mentions: Detailed spectra in the Ce 3d, Sn 3d, and O 1s core level regions are shown in Figure 3. CeO2 has a relatively complex Ce 3d XPS spectrum that consists of six peaks, which correspond to the three pairs of spin-orbit doublets of oxidized CeO2 [13]. The measured Ce 3d spectrum (Figure 3(a)) clearly shows five peaks at binding energies of 882.4 eV, 888.1 eV, 897.8 eV, 900.4 eV, and 906.7 eV. The first three peaks correspond to Ce 3d5/2 and the last two peaks correspond to Ce 3d3/2. An additional peak at a binding energy of 916.6 eV was observed in the survey scan (shown by the arrow in Figure 2).

Bottom Line: The films were investigated for the detection of carbon monoxide, and were found to be highly sensitive.We found that 430 °C was the optimum operating temperature for sensing CO gas at concentrations as low as 5 ppm.Our sensors exhibited fast response and recovery times of 26 s and 30 s, respectively.

View Article: PubMed Central - PubMed

Affiliation: Physics Department, King Fahd University of Petroleum and Minerals, Dhahran 31261, Saudi Arabia. smayub@kfupm.edu.sa

ABSTRACT
Thin films of tin oxide mixed cerium oxide were grown on unheated substrates by physical vapor deposition. The films were annealed in air at 500 °C for two hours, and were characterized using X-ray photoelectron spectroscopy, atomic force microscopy and optical spectrophotometry. X-ray photoelectron spectroscopy and atomic force microscopy results reveal that the films were highly porous and porosity of our films was found to be in the range of 11.6-21.7%. The films were investigated for the detection of carbon monoxide, and were found to be highly sensitive. We found that 430 °C was the optimum operating temperature for sensing CO gas at concentrations as low as 5 ppm. Our sensors exhibited fast response and recovery times of 26 s and 30 s, respectively.

Show MeSH