Intelligent Gas Detection: g-C₃N₄/Polypyrrole Decorated Alginate Paper as Smart Selective NH₃/NO₂ Sensors at Room...

Area of Science:

• Materials Science
• Chemical Sensors
• Nanotechnology

Background:

• Chemiresistive sensors for ammonia (NH3) and nitrogen dioxide (NO2) are crucial for air quality monitoring but face challenges like cross-sensitivity and high power consumption.
• Inadequate charge-transfer capabilities of existing gas-sensing materials limit sensor performance.

Purpose of the Study:

• To develop a flexible, room-temperature sensor for simultaneous NH3 and NO2 detection with enhanced performance.
• To investigate the potential of graphitic carbon nitride/polypyrrole decorated alginate paper (AP@g-CN/PPy) as a gas-sensing material.
• To establish an intelligent strategy for hazardous gas identification using deep learning.

Main Methods:

• Fabrication of a flexible sensor using alginate paper decorated with graphitic carbon nitride (g-CN) and polypyrrole (PPy).
• Testing the sensor's response to varying concentrations of NH3 and NO2 at room temperature.
• Evaluating sensor performance including sensitivity, selectivity, stability, flexibility, and humidity resilience.
• Developing a deep learning model utilizing transient response features for gas recognition.

Main Results:

• The AP@g-CN/PPy sensor demonstrated significant positive and negative responses to NH3 and NO2 (0.1-5 ppm) at room temperature.
• The sensor exhibited substantially higher sensitivity (∼4.5x for NH3, ∼7.0x for NO2) compared to pristine PPy.
• The flexible sensor showed excellent reproducibility, long-term stability, anti-interference, and humidity resilience.
• A deep learning model successfully achieved qualitative recognition of gases using 9 extracted transient response features.

Conclusions:

• The developed AP@g-CN/PPy sensor offers a promising alternative for dual NH3/NO2 sensing at room temperature.
• The integration of deep learning provides an intelligent approach for reliable hazardous gas identification in complex environments.
• This work advances the development of high-performance, flexible gas sensors for practical applications.