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Highly Sensitive H2S Sensor Based on the Metal-Catalyzed SnO2 Nanocolumns Fabricated by Glancing Angle Deposition.

Yoo KS, Han SD, Moon HG, Yoon SJ, Kang CY - Sensors (Basel) (2015)

Bottom Line: After annealing at 500 °C for 40 h, the sensors showed a polycrystalline phase with a porous, tilted columnar nanostructure.The gas sensitivities (S = Rgas/Rair) of Au and Ag-catalyzed SnO2 sensors fabricated by the GAD process were 0.009 and 0.015, respectively, under 5 ppm H2S at 300 °C, and the 90% response time was approximately 5 s.These sensors showed excellent sensitivities compared with the SnO2 thin film sensors that were deposited normally (glancing angle = 0°, S = 0.48).

View Article: PubMed Central - PubMed

Affiliation: Department of Materials Science and Engineering, University of Seoul, 163, Seoulsiripdae-ro, Dongdaemun-gu, Seoul 130-743, Korea. ksyoo@uos.ac.kr.

ABSTRACT
As highly sensitive H2S gas sensors, Au- and Ag-catalyzed SnO2 thin films with morphology-controlled nanostructures were fabricated by using e-beam evaporation in combination with the glancing angle deposition (GAD) technique. After annealing at 500 °C for 40 h, the sensors showed a polycrystalline phase with a porous, tilted columnar nanostructure. The gas sensitivities (S = Rgas/Rair) of Au and Ag-catalyzed SnO2 sensors fabricated by the GAD process were 0.009 and 0.015, respectively, under 5 ppm H2S at 300 °C, and the 90% response time was approximately 5 s. These sensors showed excellent sensitivities compared with the SnO2 thin film sensors that were deposited normally (glancing angle = 0°, S = 0.48).

No MeSH data available.


Gas-sensing properties of the sensors exposed to 5 ppm H2S at 300 °C. (a) SnO2 thin film sensor; (b) SnO2 nanocolumn sensor; (c) Au-catalyzed SnO2 nanocolumn sensor; (d) Ag-catalyzed SnO2 nanocolumn sensor.
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sensors-15-15468-f004: Gas-sensing properties of the sensors exposed to 5 ppm H2S at 300 °C. (a) SnO2 thin film sensor; (b) SnO2 nanocolumn sensor; (c) Au-catalyzed SnO2 nanocolumn sensor; (d) Ag-catalyzed SnO2 nanocolumn sensor.

Mentions: Figure 4 shows the H2S gas-sensing properties of the SnO2 sensors at an operating temperature of 300 °C and their sensitivities are summarized in Table 1. As shown in Figure 4a, the resistance of the SnO2 thin film sensor in dry air was 107.57 Ω (Rair), but its resistance when it was exposed to the 5 ppm H2S gas decreased to 51.23 Ω (Rgas), resulting in a gas sensitivity (S = Rgas/Rair) of 0.48. This change can be explained by Equation (4), and the result is similar to those from previous studies [32].


Highly Sensitive H2S Sensor Based on the Metal-Catalyzed SnO2 Nanocolumns Fabricated by Glancing Angle Deposition.

Yoo KS, Han SD, Moon HG, Yoon SJ, Kang CY - Sensors (Basel) (2015)

Gas-sensing properties of the sensors exposed to 5 ppm H2S at 300 °C. (a) SnO2 thin film sensor; (b) SnO2 nanocolumn sensor; (c) Au-catalyzed SnO2 nanocolumn sensor; (d) Ag-catalyzed SnO2 nanocolumn sensor.
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Related In: Results  -  Collection

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getmorefigures.php?uid=PMC4541839&req=5

sensors-15-15468-f004: Gas-sensing properties of the sensors exposed to 5 ppm H2S at 300 °C. (a) SnO2 thin film sensor; (b) SnO2 nanocolumn sensor; (c) Au-catalyzed SnO2 nanocolumn sensor; (d) Ag-catalyzed SnO2 nanocolumn sensor.
Mentions: Figure 4 shows the H2S gas-sensing properties of the SnO2 sensors at an operating temperature of 300 °C and their sensitivities are summarized in Table 1. As shown in Figure 4a, the resistance of the SnO2 thin film sensor in dry air was 107.57 Ω (Rair), but its resistance when it was exposed to the 5 ppm H2S gas decreased to 51.23 Ω (Rgas), resulting in a gas sensitivity (S = Rgas/Rair) of 0.48. This change can be explained by Equation (4), and the result is similar to those from previous studies [32].

Bottom Line: After annealing at 500 °C for 40 h, the sensors showed a polycrystalline phase with a porous, tilted columnar nanostructure.The gas sensitivities (S = Rgas/Rair) of Au and Ag-catalyzed SnO2 sensors fabricated by the GAD process were 0.009 and 0.015, respectively, under 5 ppm H2S at 300 °C, and the 90% response time was approximately 5 s.These sensors showed excellent sensitivities compared with the SnO2 thin film sensors that were deposited normally (glancing angle = 0°, S = 0.48).

View Article: PubMed Central - PubMed

Affiliation: Department of Materials Science and Engineering, University of Seoul, 163, Seoulsiripdae-ro, Dongdaemun-gu, Seoul 130-743, Korea. ksyoo@uos.ac.kr.

ABSTRACT
As highly sensitive H2S gas sensors, Au- and Ag-catalyzed SnO2 thin films with morphology-controlled nanostructures were fabricated by using e-beam evaporation in combination with the glancing angle deposition (GAD) technique. After annealing at 500 °C for 40 h, the sensors showed a polycrystalline phase with a porous, tilted columnar nanostructure. The gas sensitivities (S = Rgas/Rair) of Au and Ag-catalyzed SnO2 sensors fabricated by the GAD process were 0.009 and 0.015, respectively, under 5 ppm H2S at 300 °C, and the 90% response time was approximately 5 s. These sensors showed excellent sensitivities compared with the SnO2 thin film sensors that were deposited normally (glancing angle = 0°, S = 0.48).

No MeSH data available.