Dual-Synthesis Ti₃C₂/SnS₂ for NH₃ Detection: High Sensitivity and Fast Response/Recovery

Area of Science:

• Materials Science
• Chemical Engineering
• Environmental Science

Background:

• Ammonia (NH3) presents significant human health and environmental risks.
• Development of high-performance NH3 sensors is crucial for monitoring and mitigation.
• Pure SnS2 sensors suffer from incomplete desorption issues.

Purpose of the Study:

• To synthesize and investigate Ti3C2/SnS2 heterojunctions for enhanced NH3 sensing.
• To compare the performance of materials prepared via vacuum filtration (Ti3C2/SnS2-F) and one-pot hydrothermal synthesis (Ti3C2/SnS2-H).
• To elucidate the sensing mechanism through first-principles calculations.

Main Methods:

• Synthesis of Ti3C2/SnS2 heterojunctions using vacuum filtration and one-pot hydrothermal methods.
• Systematic investigation of gas-sensing performance, including response range, response/recovery time, stability, and selectivity.
• First-principles calculations to understand interfacial electron transfer and NH3 adsorption effects.

Main Results:

• Ti3C2/SnS2-F exhibited a wide response range (10-500 ppm NH3), response value of 11, fast response/recovery (15 s/44 s), and excellent long-term stability.
• Ti3C2/SnS2-H showed a good linear response (10-300 ppm NH3) and low baseline resistance.
• Both heterojunctions demonstrated excellent selectivity for NH3 and resolved the desorption issue of pure SnS2.
• Calculations confirmed electron transfer at the Ti3C2/SnS2 interface, forming a charge-layered structure that enhances sensing via carrier distribution modulation.

Conclusions:

• Ti3C2/SnS2 heterojunctions are promising materials for high-performance NH3 sensors.
• The combination of SnS2 and Ti3C2 effectively enhances NH3 sensing properties.
• This work provides a novel strategy for designing advanced gas-sensing materials.