1D/2D Heterostructured WS₂@PANI Composite for Highly Sensitive, Flexible, and Room Temperature Ammonia Gas Sensor

Area of Science:

• Materials Science
• Nanotechnology
• Chemical Sensing

Background:

• Room-temperature (RT) ammonia gas sensors are crucial for exhaled breath analysis.
• Two-dimensional transition metal disulfides offer potential for RT gas sensing due to their electronic properties and abundant edge sites.

Purpose of the Study:

• To develop a novel 1D/2D heterostructured composite for enhanced ammonia gas sensing.
• To investigate the synergistic effects of tungsten disulfide (WS2) and polyaniline (PANI) in a WS2@PANI sensor.

Main Methods:

• Fabrication of a WS2@PANI heterostructure with fibrous PANI modifying 2D WS2 nanosheets.
• Gas sensing performance evaluation at room temperature, including selectivity, reproducibility, and response/recovery times.
• Investigation of the sensing mechanism using complex impedance spectra and in situ Fourier-transform infrared spectroscopy (FT-IR).

Main Results:

• The WS2@PANI sensor exhibited high selectivity, reproducibility, and long-term stability for ammonia detection.
• Achieved a significant response of 216.3% and rapid response/recovery times (25 s/39 s) for 100 ppm ammonia.
• Demonstrated resistance to thermal and humidity interference, indicating robust performance.

Conclusions:

• The synergistic interaction between WS2 and PANI enhances ammonia gas sensing capabilities.
• The WS2@PANI sensor shows significant potential for non-invasive human exhaled breath detection.
• The developed material is suitable for applications in wearable electronics and advanced gas sensing technologies.