Pt-modified hollow tube-like polyaniline-based NH₃ sensor.

Area of Science:

• Materials Science
• Chemical Engineering
• Environmental Science

Background:

• Polyaniline (PANI) is suitable for room-temperature ammonia (NH3) detection due to its electrical properties and synthesis ease.
• Pristine PANI exhibits limitations in sensitivity, response speed, and detection limits for NH3 sensing.

Purpose of the Study:

• To enhance the performance of PANI-based NH3 sensors by addressing low sensitivity and high detection limits.
• To develop a novel platinum (Pt)-modified hollow PANI (Pt-PANI) gas sensor for improved NH3 detection.

Main Methods:

• Fabrication of Pt-PANI using an in-situ sacrificial template method with Pt-MnO2 nanowires.
• Utilizing acid-induced polymerization of aniline on nanowire surfaces, leveraging sacrificial reaction potential.
• Characterization of the hollow tube-like structure with embedded Pt particles for gas diffusion and electron transfer.

Main Results:

• The Pt-PANI-3 sensor achieved a low NH3 detection limit of 20.3 ppb.
• Sensitivity to 20 ppm NH3 increased 17-fold compared to pure PANI.
• Demonstrated reproducibility and long-term stability in NH3 gas sensing.

Conclusions:

• The Pt-PANI hollow structure with Pt nanoparticles significantly improves NH3 sensing performance.
• Pt-PANI sensors offer a promising solution for real-time environmental monitoring of NH3.
• Schottky junctions formed by Pt particles enhance gas sensing reactions and resistance changes.