Medium-Low-Temperature NO2 Sensor Based on YSZ Solid Electrolyte and Mesoporous WO3 Sensing Electrode for Detection of Vehicle Emissions

NANO ◽  
2021 ◽  
pp. 2150083
Author(s):  
Cheng Zhang ◽  
Chuning Jiang ◽  
Xiaohong Zheng ◽  
Xin Hong
Keyword(s):  
Low Temperature ◽  
Electromotive Force ◽  
Electrochemical Impedance ◽  
Yttria Stabilized Zirconia ◽  
Mixed Potential ◽  
Stabilized Zirconia ◽  
Excellent Performance ◽  
Hard Template ◽  
No2 Sensor ◽  
Hard Template Method

A mixed potential-type NO2 sensor was fabricated using yttria-stabilized zirconia (YSZ) as the electrolyte and mesoporous WO3 as the sensing electrode for the detection of NO2 in vehicle exhausts. The mesoporous WO3 with a diameter of 7 nm was synthesized using the hard template method. The sensor showed excellent performance in the detection of 30–500[Formula: see text]ppm of NO2 at 300∘C and 500∘C. However, commercial WO3 only operate well at 500∘C. The response of the mesoporous WO3 was higher and the test temperature was lower compared to that of commercial WO3. XPS combined with NO2-TPD was used to explain the high activity of mesoporous WO3 at medium-low temperature, and the mechanism of mixed electromotive force was verified by electrochemical impedance spectroscopy. Furthermore, the sensor exhibited high NO2 selectivity in the presence of interfering gases, such as NO, CO, CO2 and NH3. Most importantly, the sensor had excellent repeatability and stability.

Characterizations of Synthetic 8mol% YSZ with Comparison to 3mol %YSZ for HT-SOFC

2020 ◽  
Vol 38 (4A) ◽  
pp. 491-500
Author(s):  
Abeer F. Al-Attar ◽  
Saad B. H. Farid ◽  
Fadhil A. Hashim
Keyword(s):  
Ionic Conductivity ◽  
Electrochemical Impedance ◽  
Structural Information ◽  
Impedance Analysis ◽  
High Energy ◽  
Yttria Stabilized Zirconia ◽  
X Ray Diffraction ◽  
Stabilized Zirconia ◽  
Powder Morphology ◽  
X Ray

In this work, Yttria (Y2O3) was successfully doped into tetragonal 3mol% yttria stabilized Zirconia (3YSZ) by high energy-mechanical milling to synthesize 8mol% yttria stabilized Zirconia (8YSZ) used as an electrolyte for high temperature solid oxide fuel cells (HT-SOFC). This work aims to evaluate the densification and ionic conductivity of the sintered electrolytes at 1650°C. The bulk density was measured according to ASTM C373-17. The powder morphology and the microstructure of the sintered electrolytes were analyzed via Field Emission Scanning Electron Microscopy (FESEM). The chemical analysis was obtained with Energy-dispersive X-ray spectroscopy (EDS). Also, X-ray diffraction (XRD) was used to obtain structural information of the starting materials and the sintered electrolytes. The ionic conductivity was obtained through electrochemical impedance spectroscopy (EIS) in the air as a function of temperatures at a frequency range of 100(mHz)-100(kHz). It is found that the 3YSZ has a higher density than the 8YSZ. The impedance analysis showed that the ionic conductivity of the prepared 8YSZ at 800°C is0.906 (S.cm) and it was 0.214(S.cm) of the 3YSZ. Besides, 8YSZ has a lower activation energy 0.774(eV) than that of the 3YSZ 0.901(eV). Thus, the prepared 8YSZ can be nominated as an electrolyte for the HT-SOFC.

scholarly journals Influence of Preaging Temperature on the Indentation Strength of 3Y-TZP Aged in Ambient Atmosphere

Materials ◽  
2021 ◽  
Vol 14 (11) ◽  
pp. 2767
Author(s):  
Ki-Won Jeong ◽  
Jung-Suk Han ◽  
Gi-Uk Yang ◽  
Dae-Joon Kim
Keyword(s):  
Residual Stress ◽  
Phase Transformation ◽  
Low Temperature ◽  
Compressive Residual Stress ◽  
Yttria Stabilized Zirconia ◽  
Ambient Atmosphere ◽  
Aged Specimen ◽  
Stabilized Zirconia ◽  
M Phase ◽  
The Relationship

Yttria-stabilized zirconia (3Y-TZP) containing 0.25% Al2O3, which is resistant to low temperature degradation (LTD), was aged for 10 h at 130–220 °C in air. The aged specimens were subsequently indented at loads ranging from 9.8 to 490 N using a Vickers indenter. The influence of preaging temperature on the biaxial strength of the specimens was investigated to elucidate the relationship between the extent of LTD and the strength of zirconia restorations that underwent LTD. The indented strength of the specimens increased as the preaging temperature was increased higher than 160 °C, which was accompanied by extensive t-ZrO2 (t) to m-ZrO2 (m) and c-ZrO2 (c) to r-ZrO2 (r) phase transformations. The influence of preaging temperature on the indented strength was rationalized by the residual stresses raised by the t→m transformation and the reversal of tensile residual stress on the aged specimen surface due to the indentation. The results suggested that the longevity of restorations would not be deteriorated if the aged restorations retain compressive residual stress on the surface, which corresponds to the extent of t→m phase transformation less than 52% in ambient environment.

scholarly journals High Performance Mixed Potential Type NO2 Gas Sensor Based on Porous YSZ Layer Formed with Graphite Doping

Sensors ◽  
2019 ◽  
Vol 19 (15) ◽  
pp. 3337 ◽  
Author(s):  
Hao Hong ◽  
Jianwen Sun ◽  
Cinan Wu ◽  
Zewen Liu
Keyword(s):  
High Performance ◽  
Sol Gel ◽  
Yttria Stabilized Zirconia ◽  
Mixed Potential ◽  
Stabilized Zirconia ◽  
No2 Gas Sensor ◽  
Potential Type ◽  
Measurement Results ◽  
Good Repeatability ◽  
Sensor Measurement

High performance mixed potential type NO2 sensors using porous yttria-stabilized zirconia (YSZ) layers doped with different concentration graphite as solid electrolyte and LaFeO3 as sensing electrode were fabricated and characterized. LaFeO3 was prepared by a typical citrate sol–gel method and characterized using XRD. The surface morphology and porosity of porous YSZ layers were characterized by field emission scanning electron microscope (FESEM). The sensor doped with 3 wt% graphite shows the highest response (−76.4 mV to 80 ppm NO2) and the response is linearly dependent on the logarithm of NO2 concentration in the range of 10–200 ppm. The sensor measurement results also present good repeatability and cross-sensitivity.

scholarly journals Electrochemical and Oxidation Behavior of Yttria Stabilized Zirconia Coating on Zircaloy-4 Synthesized via Sol-Gel Process

2013 ◽  
Vol 2013 ◽  
pp. 1-9 ◽  
Author(s):  
S. Rezaee ◽  
Gh. R. Rashed ◽  
M. A. Golozar
Keyword(s):  
Heat Treatment ◽  
Electrochemical Impedance ◽  
Sol Gel ◽  
Dip Coating ◽  
Open Circuit ◽  
Treatment Temperature ◽  
Yttria Stabilized Zirconia ◽  
Coated Sample ◽  
Stabilized Zirconia ◽  
Temperature Oxidation

Sol-gel 8 wt.% Yttria Stabilized Zirconia (YSZ) thin films were prepared on zirconium (zircaloy-4 alloy) by dip-coating technique followed by heat treating at various temperatures (200°C, 400°C, and 700°C) in order to improve both electrochemical corrosion and high temperature oxidation properties of the substrate. Differential thermal analysis and thermogravimetric analysis (DTA-TG) revealed the coating formation process. X-ray diffraction (XRD) was used to determine the crystalline phase structure transformation. The morphological characterization of the coatings was carried out using scanning electron microscopy (SEM). The electrochemical behavior of the coated and uncoated samples was investigated by means of open circuit potential, Tafel, and electrochemical impedance spectroscopy (EIS) in a 3.5 wt.% NaCl solution. The homogeneity and surface appearance of coatings produced was affected by the heat treatment temperature. According to the corrosion parameters, the YSZ coatings showed a considerable increase in the corrosion resistance, especially at higher heat treatment temperatures. The coating with the best quality, from the surface and corrosion point of view, was subjected to oxidation test in air at 800°C. The coated sample presented a 25% reduction in oxidation rate in comparison with bare substrate.

Electrospun yttria-stabilized zirconia nanofibers for low-temperature solid oxide fuel cells

2017 ◽  
Vol 42 (24) ◽  
pp. 15903-15907 ◽  
Author(s):  
Ja Yang Koo ◽  
Yonghyun Lim ◽  
Young Beom Kim ◽  
Doyoung Byun ◽  
Wonyoung Lee
Keyword(s):  
Fuel Cells ◽  
Low Temperature ◽  
Solid Oxide Fuel Cells ◽  
Solid Oxide ◽  
Yttria Stabilized Zirconia ◽  
Oxide Fuel ◽  
Stabilized Zirconia

Miniaturized Low-temperature Solid Oxide Fuel Cells with an Yttria-stabilized-zirconia Foil Electrolyte

2019 ◽  
Vol 25 (2) ◽  
pp. 989-993 ◽  
Author(s):  
Anna Evans ◽  
Anja Bieberle-Hutter ◽  
Lorenz J. Bonderer ◽  
Philipp Chen ◽  
Damian Hodel ◽  
...  
Keyword(s):  
Fuel Cells ◽  
Low Temperature ◽  
Solid Oxide Fuel Cells ◽  
Solid Oxide ◽  
Yttria Stabilized Zirconia ◽  
Oxide Fuel ◽  
Stabilized Zirconia
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