High-Response Room-Temperature NO₂ Sensor and Ultrafast Humidity Sensor Based on SnO₂ with Rich Oxygen Vacancy

Area of Science:

• Materials Science
• Nanotechnology
• Chemical Sensing

Background:

• Tin oxide (SnO2) is a promising material for gas sensors.
• Enhancing SnO2 properties through defect engineering is crucial for improved performance.
• Developing efficient room-temperature sensors remains a challenge.

Purpose of the Study:

• To synthesize tin oxide nanosheets with abundant oxygen vacancies (SnO2-x).
• To investigate the gas sensing properties of SnO2-x for NO2 and humidity.
• To explore the structure-property relationship for enhanced sensing.

Main Methods:

• Synthesis of SnO2-x nanosheets via annealing SnSe nanosheets.
• Characterization using transmission electron microscopy (TEM).
• Gas sensing measurements for NO2 and humidity at room temperature.

Main Results:

• Successfully prepared SnO2-x nanosheets with high-density oxygen vacancies.
• Achieved excellent NO2 sensing performance (response=16 to 5 ppm NO2) at room temperature.
• Demonstrated ultrafast humidity sensing (response=52 ms, recovery=140 ms).

Conclusions:

• The synthesized SnO2-x nanosheets exhibit superior room-temperature NO2 sensing capabilities.
• The material shows competitive performance for humidity sensing.
• The abundant oxygen vacancies and unique nanostructure are key to the enhanced sensing.