Nb₂CT_x/MoSe₂ composites for a highly sensitive NH₃ gas sensor at room temperature

Area of Science:

• Materials Science
• Nanotechnology
• Chemical Sensing

Background:

• Ammonia (NH3) gas detection is crucial for industrial processes and daily life.
• Developing sensitive and stable NH3 sensors is an ongoing research challenge.

Purpose of the Study:

• To synthesize and evaluate a Nb2CTx/MoSe2 composite sensor for NH3 detection.
• To investigate the sensing mechanism and performance characteristics of the composite material.

Main Methods:

• One-step hydrothermal synthesis of Nb2CTx/MoSe2 composite.
• Characterization using XRD, TEM, SEM, and XPS.
• Room-temperature NH3 sensing performance testing (0.1-100 ppm).

Main Results:

• The Nb2CTx/MoSe2 sensor demonstrated a 3.5-fold increase in response to 50 ppm NH3 compared to pure Nb2CTx.
• Significantly reduced response/recovery times (56.4 s/32.1 s).
• Excellent long-term stability with <10% variation over 90 days.

Conclusions:

• The Nb2CTx/MoSe2 composite exhibits superior NH3 sensing performance due to p-n heterojunction formation and charge transfer.
• The material shows potential for practical NH3 detection applications.
• First-principles calculations elucidated the selectivity mechanism for NH3.