Highly Sensitive and Selective Hydrogen Gas Sensor Using the Mesoporous SnO₂ Modified Layers

Area of Science:

• Materials Science
• Chemical Engineering
• Sensor Technology

Background:

• Metal oxide semiconductor (MOS) gas sensors require improved sensitivity and selectivity for hydrogen monitoring.
• Applications in aerospace and electronics necessitate reliable hydrogen detection.
• Tin dioxide (SnO₂) is a key material for gas sensing applications.

Purpose of the Study:

• To enhance the sensitivity and selectivity of SnO₂-based gas sensors.
• To investigate the effect of ordered mesoporous SnO₂ (m-SnO₂) modification on commercial SnO₂ (c-SnO₂) gas sensors.
• To explore the gas sensing performance towards ethanol, benzene, and hydrogen.

Main Methods:

• Ordered mesoporous SnO₂ (m-SnO₂) powders synthesized via sol-gel method.
• Material characterization using X-ray diffraction analysis (XRD), transmission electron microscope (TEM), and Brunauer-Emmett-Teller (BET).
• Gas sensor fabrication using screen printing technology with m-SnO₂ modified c-SnO₂ layers.

Main Results:

• Modified m-SnO₂ layers on c-SnO₂ significantly improved gas sensor sensitivity.
• The S(c/m2) sensor demonstrated the highest response (Ra/Rg = 22.2) to 1000 ppm hydrogen at 400 °C.
• Optimized operating temperatures ranged from 200 °C to 400 °C for various gases.

Conclusions:

• The use of ordered mesoporous SnO₂ enhances the performance of SnO₂ gas sensors.
• The developed sensors show promise for accurate hydrogen detection in demanding environments.
• Further investigation into the underlying mechanisms of sensitivity and selectivity improvement is warranted.