Surface Defect-Induced Specific Catalysis Activates 100% Selective Sensing toward Amine Gases at Room Temperature

Area of Science:

• Materials Science
• Chemical Sensing
• Nanotechnology

Background:

• Selective sensing of volatile organic compounds (VOCs) is crucial for environmental monitoring and diagnostics.
• Existing chemiresistive sensors lack the specificity of biological enzymes in complex gas mixtures.

Purpose of the Study:

• To develop a chemiresistive sensor with high selectivity towards amine gases at room temperature.
• To investigate the mechanism behind the specific catalytic activity induced by defect engineering.

Main Methods:

• Optimizing oxygen vacancy structures in tin oxide (SnO2) materials.
• Utilizing in situ technologies and theoretical calculations to analyze surface interactions.
• Fabricating and testing chemiresistive sensors for amine gas detection.

Main Results:

• Achieved 100% selective sensing of amine gases at room temperature.
• Identified specific "donor-receptor" coordination between amine nitrogen atoms and bridging oxygen vacancies (OV_Bri) as the key mechanism.
• Demonstrated record-high sensing values for triethylamine, trimethylamine, and diethylamine.

Conclusions:

• Defect engineering in tin oxide, specifically optimizing oxygen vacancies, can induce specific catalytic activity for selective gas sensing.
• The developed sensor exhibits high selectivity and sensitivity towards amines, even in mixed gas environments.
• This approach offers a pathway for advancing highly selective and sensitive room-temperature gas sensors.