Resistive Oxygen Gas Sensing Behavior of Zirconia-Doped Ceria

2011 ◽  
Vol 479 ◽  
pp. 143-148
Author(s):  
Kai Hsin Chang ◽  
Chin Lung Liu ◽  
Ya Ting Chan ◽  
Wen Cheieh Tsai ◽  
Chin Yi Chen
Keyword(s):  
Electrical Conductivity ◽  
Gas Sensing ◽  
Precipitation Method ◽  
Doped Ceria ◽  
Irregular Shapes ◽  
Nanocrystalline Ceria ◽  
Partial Pressures ◽  
Coating Morphology ◽  
Oxygen Gas ◽  
Co Precipitation

In the present study, nanocrystalline ceria powder and 10 mol% zirconia-doped ceria (10ZDC) powder were prepared by co-precipitation method from cerium nitrate and zirconium nitrate precursors. The resulting particles with irregular shapes were printed onto alumina substrate for the investigation of oxygen gas sensing behavior. The coating morphology of 10ZDC with a network structure revealed a better connection enhancing the sensing properties. Zirconia doping tended to inhibit the grain growth and decrease the lattice constant of ceria. Such effects may improve the electrical conductivity of 10ZDC under different oxygen partial pressures and shorten the response time of 10ZDC to the change of oxygen partial pressure.

Preparation and Characterization of Nanocomposite Calcium Doped Ceria Electrolyte With Alkali Carbonates (NK-CDC) for SOFC

2010 ◽  
Author(s):  
Ghazanfar Abbas ◽  
Rizwan Raza ◽  
Muhammad Ashraf Chaudhry ◽  
Bin Zhu
Keyword(s):  
Electron Microscopy ◽  
Fossil Fuels ◽  
Electrochemical Impedance ◽  
Renewable Energy Sources ◽  
Precipitation Method ◽  
Molar Ratio ◽  
Doped Ceria ◽  
Alternative Source ◽  
Calcium Doped ◽  
Co Precipitation

The entire world’s challenge is to find out the renewable energy sources due to rapid depletion of fossil fuels because of their high consumption. Solid Oxide Fuel Cells (SOFCs) are believed to be the best alternative source which converts chemical energy into electricity without combustion. Nanostructured study is required to develop highly ionic conductive electrolyte for SOFCs. In this work, the calcium doped ceria (Ce0.8Ca0.2O1.9) coated with 20% molar ratio of two alkali carbonates (CDC-M: MCO3, where M = Na and K) electrolyte was prepared by co-precipitation method in this study. Ni based electrode was used to fabricate the cell by dry pressing technique. The crystal structure and surface morphology was characterized by X-Ray Diffractometer (XRD), Scanning Electron Microscopy (SEM) and High Resolution Transmission Electron Microscopy (HRTEM). The particle size was calculated in the range of 10–20nm by Scherrer’s formula and compared with SEM and TEM results. The ionic conductivity was measured by using AC Electrochemical Impedance Spectroscopy (EIS) method. The activation energy was also evaluated. The performance of the cell was measured 0.567W/cm2 at temperature 550°C with hydrogen as a fuel.

Superior sinterability of nano-crystalline gadolinium doped ceria powders synthesized by co-precipitation method

2010 ◽  
Vol 495 (1) ◽  
pp. 238-241 ◽  
Author(s):  
D. Hari Prasad ◽  
H.-R. Kim ◽  
J.-S. Park ◽  
J.-W. Son ◽  
B.-K. Kim ◽  
...  
Keyword(s):  
Precipitation Method ◽  
Doped Ceria ◽  
Nano Crystalline ◽  
Co Precipitation ◽  
Gadolinium Doped Ceria

scholarly journals Effect of Zn Doping in CuO Octahedral Crystals towards Structural, Optical, and Gas Sensing Properties

Crystals ◽  
2020 ◽  
Vol 10 (3) ◽  
pp. 188 ◽  
Author(s):  
Chandra Prakash Goyal ◽  
Deepak Goyal ◽  
Sinjumol K. Rajan ◽  
Niranjan S. Ramgir ◽  
Yosuke Shimura ◽  
...  
Keyword(s):  
Work Function ◽  
Surface Defects ◽  
Gas Sensing ◽  
Oxygen Adsorption ◽  
Precipitation Method ◽  
Zn Doping ◽  
Sensor Resistance ◽  
Sensing Applications ◽  
Zinc Doping ◽  
Co Precipitation

Monodispersed CuO octahedral crystals were successfully synthesized using a low-temperature co-precipitation method. Zinc doping in CuO created surface defects that enhanced oxygen adsorption on the surface crucial for gas sensing applications. Pure and Zn-doped CuO sensor films were realized using the doctor blade method. The sensor films showed selective response towards a low concentration of NO2 at a lower operating temperature of 150 °C. Doping with Zn causes the resistance of the sensor film to decrease due to the enhancement of charge carriers with an analogous improvement in the sensor response. The observed decrease in sensor resistance agreed well with the findings of the work function studies. Zinc doping resulted in an increase in work function by 180 meV which, after NO2 exposure, was found to increase by a further 130 meV, attributed to the oxidizing behavior of the test gas.

Effect of Doping Concentration on Grain Boundary Conductivity of Samaria Doped Ceria Composites

2021 ◽  
Author(s):  
Prerna Vinchhi ◽  
Roma Patel ◽  
Indrajit Mukhopadhyay ◽  
Abhijit Ray ◽  
Ranjan Pati
Keyword(s):  
Ionic Conductivity ◽  
Grain Boundary ◽  
Doping Concentration ◽  
Single Phase ◽  
Precipitation Method ◽  
Molecular Water ◽  
Doped Ceria ◽  
Boundary Conductivity ◽  
Co Precipitation ◽  
Hydrated Oxide

Abstract This work aims to study the effect of Sm3+ doping concentration on the grain boundary ionic conductivity of ceria. The materials were prepared by a modified co-precipitation method, where molecular water associated with the precursor has been utilized to facilitate the hydroxylation process. The synthesized hydroxide / hydrated oxide materials were calcined and the green body (pellet) has been sintered at high temperature in order to achieve highly dense (~ 96 %) pellet. The structural analyses were done using XRD and Raman spectroscopy, which confirm the single phase cubic structure of samaria doped ceria (SDC) nanoparticles and the surface morphology of sintered samples was studied using FESEM. The ionic conductivity was measured by AC impedance spectroscopy of the sintered pellets in the temperature range of 400-700 °C, which shows superior grain boundary conductivity. The grain boundary ionic conductivity of around 0.111 S/cm has been obtained for 15SDC composition at 600 °C.

Gas sensing properties of magnesium ferrite prepared by co-precipitation method

2009 ◽  
Vol 488 (1) ◽  
pp. 270-272 ◽  
Author(s):  
P.P. Hankare ◽  
S.D. Jadhav ◽  
U.B. Sankpal ◽  
R.P. Patil ◽  
R. Sasikala ◽  
...  
Keyword(s):  
Gas Sensing ◽  
Precipitation Method ◽  
Magnesium Ferrite ◽  
Sensing Properties ◽  
Gas Sensing Properties ◽  
Co Precipitation

Influence of Doping on Structure and H2 Sensitivity of Nano-SnO2

2010 ◽  
Vol 96 ◽  
pp. 105-110 ◽  
Author(s):  
Hai Feng Liu ◽  
Tong Jiang Peng ◽  
Hong Juan Sun ◽  
Liang Fan ◽  
Boa Gang Guo
Keyword(s):  
Gas Sensing ◽  
Precipitation Method ◽  
X Ray Diffraction ◽  
Gas Sensitivity ◽  
X Ray ◽  
Sensing Material ◽  
Crystal Properties ◽  
Co Precipitation ◽  
Special Environment ◽  
Semiconductor Properties

In order to improve the gas sensitivity of SnO2, Ni-doped and Co-doped nano-powders were prepared by the homogenous co-precipitation method using analytical pure SnCl4•5H2O and NH3•H2O as main materials under different doped ratios n (M2+)/n (Sn4+). The gas sensors were made by the thick film technique on mica substrates. The structure and crystal properties of the samples were investigated by X-ray diffraction (XRD). The results indicated that Sn4+ in the crystal lattice of SnO2 was partly replaced by M2+, which resulted in the change of the M-O bond lengths and the lattice parameters. The sensitivities of the sensors in H2 atmosphere with different concentrations at 75°C were tested. As a result, doped M2+ especially Ni2+ improves its H2 sensitivity, the sensitivities increases linearly with the increasing H2 concentration, and the best doping n(M2+)/n(Sn4+) of preparing gas-sensing material were obtained. The results show that doping which leads to the asymmetry of electrovalent balance of M-O octahedrons improves the activities and semiconductor properties of the powders. These studies play an important part in detecting reductive gases in special environment.

Nd 3+ Substituted Nanocrystalline Zinc Ferrite Sensors for Ethanol, LPG and Chlorine

2013 ◽  
Vol 310 ◽  
pp. 150-153 ◽  
Author(s):  
Pramod N. Vasambekar ◽  
Tukaram J. Shinde ◽  
Ashok B. Gadkari
Keyword(s):  
Zinc Ferrite ◽  
Gas Sensing ◽  
Operating Temperature ◽  
Maximum Sensitivity ◽  
Precipitation Method ◽  
Chemical Formula ◽  
Response Recovery ◽  
Gas Sensing Properties ◽  
Recovery Times ◽  
Co Precipitation

Nd 3+ substituted zinc ferrites with chemical formula ZnNdxFe 2-x O4 (x = 0, 0.01, 0.02, and 0.03) were prepared by oxalate co-precipitation method and characterized by XRD, IR and SEM techniques. The gas sensing properties were studied for ethanol, LPG and chlorine. It was observed that nanocrystalline ZnFe2O4 shows maximum sensitivity to ethanol (~41%) followed by LPG (~22%) and less sensitivity to Cl2 (~10%) at an operating temperature of 327oC. The sensitivity of zinc ferrites increases with increase in Nd 3+ content. Response-recovery times of zinc ferrite decreases with increase in Nd3+ content.

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