Highly sensitive NO₂ gas sensors based on hexagonal SnS₂ nanoplates operating at room temperature

Area of Science:

• Materials Science
• Nanotechnology
• Chemical Sensing

Background:

• Reducing power consumption in chemoresistive gas sensors is crucial for practical applications.
• Enabling gas sensors to operate near room temperature is an efficient strategy for low-power sensing.

Purpose of the Study:

• To develop a highly sensitive and reversible gas sensor for nitrogen dioxide (NO₂) detection at room temperature.
• To explore the potential of hexagonal tin disulfide (SnS₂) nanoplates for low-operating-temperature gas sensing.

Main Methods:

• Synthesis of two-dimensional (2D) SnS₂ nanoplates using a facile hydrothermal method with Triton X-100 surfactant.
• Fabrication and characterization of a chemoresistive gas sensor based on the synthesized SnS₂ nanoplates.
• Evaluation of sensor performance for NO₂ detection at room temperature, including response, limit of detection, selectivity, and stability.

Main Results:

• The SnS₂ nanoplate sensor achieved a high response of 15.6 to 50 ppm NO₂ at room temperature.
• An experimental limit of detection (LOD) of 50 ppb for NO₂ was demonstrated.
• The sensor exhibited excellent linearity, outstanding selectivity, and reliable long-term stability over 40 days.

Conclusions:

• The developed SnS₂ nanoplate-based sensor enables sensitive and reversible NO₂ detection at room temperature.
• The sensing mechanism involves physisorption and charge transfer between NO₂ and SnS₂, facilitating low-temperature operation.
• This research offers a promising pathway for effective and low-power NO₂ detection.