A limiting Current Oxygen Sensor Constituted of(CeO2)0.95(Y2O3)0.05 as Solid Electrolyte Layer...

Area of Science:

• Materials Science
• Electrochemistry
• Sensor Technology

Background:

• Developing advanced oxygen sensors is crucial for precise monitoring in various industrial and environmental applications.
• Solid electrolytes like doped ceria offer promising properties for high-temperature electrochemical devices.
• Understanding the interplay between material properties and sensor performance is key to optimizing device design.

Purpose of the Study:

• To synthesize and characterize yttria-doped ceria (YDC) and zirconia-doped ceria (ZDC) for oxygen sensor applications.
• To fabricate a limiting current oxygen sensor utilizing YDC as the solid electrolyte and ZDC as a diffusion barrier.
• To evaluate the sensing characteristics and long-term stability of the fabricated oxygen sensor under varying operational conditions.

Main Methods:

• Co-precipitation and solid-state reaction methods were employed for synthesizing YDC and ZDC materials, respectively.
• X-ray diffraction (XRD) and scanning electron microscopy (SEM) were used to analyze the phase structure and microstructure.
• DC van Pauw and Hebb-Wagner methods were utilized to measure total and electronic conductivity.
• A limiting current oxygen sensor was constructed using platinum pasting bonding.

Main Results:

• Both YDC and ZDC exhibited a cubic crystal structure and dense microstructures, suitable for sensor components.
• The fabricated oxygen sensor demonstrated good sensing characteristics that align with the Knudsen model.
• Sensor performance showed a strong linear dependence on temperature and oxygen concentration, with minimal impact from water vapor.
• Excellent long-term stability was confirmed through continuous operation for 120 hours at 800 °C.

Conclusions:

• YDC and ZDC are viable materials for constructing high-performance limiting current oxygen sensors.
• The developed sensor exhibits reliable and stable performance, unaffected by humidity.
• This research contributes to the advancement of solid-state oxygen sensing technology.