A Highly Sensitive Ammonia Gas Sensor Using Micrometer-Sized Core-Shell-Type Spherical Polyaniline Particles

Area of Science:

• Materials Science
• Chemical Engineering
• Sensor Technology

Background:

• Ammonia (NH3) gas detection is crucial for environmental monitoring and industrial safety.
• Developing highly sensitive and room-temperature operating gas sensors remains a challenge.

Purpose of the Study:

• To fabricate and characterize a highly sensitive NH3 gas sensor using micrometer-sized polyaniline (PANI) spheres.
• To investigate the effect of microsphere size on sensor performance.

Main Methods:

• Polyaniline (PANI) microspheres with a core-shell structure were synthesized via in situ chemical oxidation polymerization.
• Polystyrene microspheres were used as templates to control PANI particle size.
• Sensor performance was evaluated by measuring the response to different concentrations of NH3 gas at room temperature.

Main Results:

• The sensor response to NH3 gas increased with increasing microsphere diameter.
• The PSt@PANI(4.5) sensor, with 4.5 μm microspheres, exhibited the highest response (77 for 100 ppm NH3) at 30 °C.
• This performance was 20 times greater than PANI film-based sensors, with a detection limit as low as 46 ppb.

Conclusions:

• Micrometer-sized PANI spherical particles are key to achieving high NH3 gas sensor sensitivity.
• This study presents a simple and effective method for developing room-temperature, high-sensitivity NH3 gas sensors.