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Potentiometric NO2 Sensors Based on Thin Stabilized Zirconia Electrolytes and Asymmetric (La0.8Sr0.2)0.95MnO3 Electrodes.

Zou J, Zheng Y, Li J, Zhan Z, Jian J - Sensors (Basel) (2015)

Bottom Line: Measurements of their sensing characteristics show that reducing the porosity of the supporting LSM95 reference electrodes can increase the response voltages.The best linear coefficient can be as high as 0.99 with a sensitivity value of 52 mV/decade as obtained at 500 °C.Analysis of the sensing mechanism suggests that the gas phase reactions within the porous LSM95 layers are critically important in determining the response voltages.

View Article: PubMed Central - PubMed

Affiliation: Gas Sensors & Sensing Technology Laboratory, College of Information Science and Engineering, Ningbo University, Ningbo 315211, China. ljl2005@mail.sic.ac.cn.

ABSTRACT
Here we report on a new architecture for potentiometric NO2 sensors that features thin 8YSZ electrolytes sandwiched between two porous (La0.8Sr0.2)0.95MnO3 (LSM95) layers-one thick and the other thin-fabricated by the tape casting and co-firing techniques. Measurements of their sensing characteristics show that reducing the porosity of the supporting LSM95 reference electrodes can increase the response voltages. In the meanwhile, thin LSM95 layers perform better than Pt as the sensing electrode since the former can provide higher response voltages and better linear relationship between the sensitivities and the NO2 concentrations over 40-1000 ppm. The best linear coefficient can be as high as 0.99 with a sensitivity value of 52 mV/decade as obtained at 500 °C. Analysis of the sensing mechanism suggests that the gas phase reactions within the porous LSM95 layers are critically important in determining the response voltages.

No MeSH data available.


Response curves of S-LSM95 and S-Pt measured in the base gas and sample gas: (a) 500 °C, 100 ppm NO2; (b) 550 °C, 100 ppm NO2 and (c) 600 °C, 100 ppm NO2.
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sensors-15-17558-f010: Response curves of S-LSM95 and S-Pt measured in the base gas and sample gas: (a) 500 °C, 100 ppm NO2; (b) 550 °C, 100 ppm NO2 and (c) 600 °C, 100 ppm NO2.

Mentions: The thick LSM95 layers with 15 wt % carbon as pore former were used further investigations. Two sensors with the same thick LSM95 layer as REs and different sensing material as SEs were tested. The voltage (V) response transients to various concentrations of NO2 (40–1000 ppm) were recorded over the temperature range of 500–600 °C for S-15LSM95 and S-15Pt. Figure 10a–c present the transient curves of two sensors tested in base gas and sample gas (NO2 100 ppm) at 500, 550 and 600 °C, respectively. Notably, we can observe that the response voltage for S-15LSM95 is higher than obtained for S-15Pt under the same measurement conditions (Figure 10a). Switching between the base gas and the sample gas, the V value of S-15LSM95 changes much more quickly than for S-15Pt, indicating faster response and recovery rates for S-15LSM95. In particular, the 90% response/recovery times are 108/126 s for S-15LSM95 and 327/288 s for S-15Pt, respectively. Increasing the measurement temperature to 550 and 600 °C yielded higher V values for S-Pt than for S-LSM95, with their transient curves compare in Figure 10b,c. The V value is close to zero under the base gas and increased more quickly than observed at 500 °C upon switching to the sample gas. The 90% response/recovery times at 550 °C are 61/61 s for S-15LSM95 and 105/185 s for S-15Pt, respectively.


Potentiometric NO2 Sensors Based on Thin Stabilized Zirconia Electrolytes and Asymmetric (La0.8Sr0.2)0.95MnO3 Electrodes.

Zou J, Zheng Y, Li J, Zhan Z, Jian J - Sensors (Basel) (2015)

Response curves of S-LSM95 and S-Pt measured in the base gas and sample gas: (a) 500 °C, 100 ppm NO2; (b) 550 °C, 100 ppm NO2 and (c) 600 °C, 100 ppm NO2.
© Copyright Policy
Related In: Results  -  Collection

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Show All Figures
getmorefigures.php?uid=PMC4541949&req=5

sensors-15-17558-f010: Response curves of S-LSM95 and S-Pt measured in the base gas and sample gas: (a) 500 °C, 100 ppm NO2; (b) 550 °C, 100 ppm NO2 and (c) 600 °C, 100 ppm NO2.
Mentions: The thick LSM95 layers with 15 wt % carbon as pore former were used further investigations. Two sensors with the same thick LSM95 layer as REs and different sensing material as SEs were tested. The voltage (V) response transients to various concentrations of NO2 (40–1000 ppm) were recorded over the temperature range of 500–600 °C for S-15LSM95 and S-15Pt. Figure 10a–c present the transient curves of two sensors tested in base gas and sample gas (NO2 100 ppm) at 500, 550 and 600 °C, respectively. Notably, we can observe that the response voltage for S-15LSM95 is higher than obtained for S-15Pt under the same measurement conditions (Figure 10a). Switching between the base gas and the sample gas, the V value of S-15LSM95 changes much more quickly than for S-15Pt, indicating faster response and recovery rates for S-15LSM95. In particular, the 90% response/recovery times are 108/126 s for S-15LSM95 and 327/288 s for S-15Pt, respectively. Increasing the measurement temperature to 550 and 600 °C yielded higher V values for S-Pt than for S-LSM95, with their transient curves compare in Figure 10b,c. The V value is close to zero under the base gas and increased more quickly than observed at 500 °C upon switching to the sample gas. The 90% response/recovery times at 550 °C are 61/61 s for S-15LSM95 and 105/185 s for S-15Pt, respectively.

Bottom Line: Measurements of their sensing characteristics show that reducing the porosity of the supporting LSM95 reference electrodes can increase the response voltages.The best linear coefficient can be as high as 0.99 with a sensitivity value of 52 mV/decade as obtained at 500 °C.Analysis of the sensing mechanism suggests that the gas phase reactions within the porous LSM95 layers are critically important in determining the response voltages.

View Article: PubMed Central - PubMed

Affiliation: Gas Sensors & Sensing Technology Laboratory, College of Information Science and Engineering, Ningbo University, Ningbo 315211, China. ljl2005@mail.sic.ac.cn.

ABSTRACT
Here we report on a new architecture for potentiometric NO2 sensors that features thin 8YSZ electrolytes sandwiched between two porous (La0.8Sr0.2)0.95MnO3 (LSM95) layers-one thick and the other thin-fabricated by the tape casting and co-firing techniques. Measurements of their sensing characteristics show that reducing the porosity of the supporting LSM95 reference electrodes can increase the response voltages. In the meanwhile, thin LSM95 layers perform better than Pt as the sensing electrode since the former can provide higher response voltages and better linear relationship between the sensitivities and the NO2 concentrations over 40-1000 ppm. The best linear coefficient can be as high as 0.99 with a sensitivity value of 52 mV/decade as obtained at 500 °C. Analysis of the sensing mechanism suggests that the gas phase reactions within the porous LSM95 layers are critically important in determining the response voltages.

No MeSH data available.