Development of Low-ppm CO Sensors Using Pristine CeO₂ Nanospheres with High Surface Area

Area of Science:

• Materials Science
• Nanotechnology
• Chemical Engineering

Background:

• Mesoporous cerium dioxide (CeO₂) exhibits unique properties beneficial for gas sensing applications.
• Developing highly sensitive and selective CO sensors is crucial for environmental and industrial safety.

Purpose of the Study:

• To synthesize mesoporous CeO₂ nanospheres using a cost-effective microemulsion method.
• To evaluate the performance of these CeO₂ nanospheres as sensors for low-ppm carbon monoxide (CO).

Main Methods:

• Preparation of mesoporous CeO₂ nanospheres via a water-in-oil microemulsion method using reversed micelles.
• Characterization of structural morphology and semiconducting properties using X-ray diffraction, electron microscopy (FESEM, TEM), and UV-visible spectroscopy.
• Fabrication and testing of packaged CO sensors under varying temperatures and gas concentrations.

Main Results:

• Mesoporous CeO₂ nanospheres with high surface area were successfully synthesized and maintained their morphology after high-temperature calcination.
• The fabricated CeO₂ nanosphere sensors demonstrated superior sensitivity (∼52%) and rapid response-recovery times (13 s) for low-ppm CO detection.
• Sensor performance was analyzed as a function of temperature and CO concentration, showing excellent selectivity.

Conclusions:

• The microemulsion method provides a scalable and cost-effective route for producing mesoporous CeO₂ nanospheres.
• Undoped CeO₂ nanospheres are highly effective for developing sensitive and selective CO gas sensors.
• These CeO₂-based sensors hold significant potential for industrial and environmental CO monitoring.