Highly Reliable Dimethyl Disulfide Chemiresistive Gas Sensor Based on Vacancy-Engineered MoO₃ Nanobelts for Complex...

Area of Science:

• Materials Science
• Environmental Science
• Chemical Sensing

Background:

• Dimethyl disulfide (DMDS) is a volatile organic compound with a strong odor, primarily emitted from sewage treatment plants.
• Existing metal-oxide DMDS gas sensors struggle with parts-per-million sensitivity and reliability, despite DMDS's health and odor concerns at ppb levels.
• Previous research focused on enhancing DMDS response through vacancy engineering, often neglecting gas reliability.

Purpose of the Study:

• To investigate a MoO3-based gas sensor for DMDS detection.
• To explore the relationship between vacancy concentration and sensor performance, particularly reliability.
• To develop a practical odor monitoring system for real-world applications.

Main Methods:

• Fabrication of MoO3-based DMDS gas sensors.
• Tuning vacancy concentration via an oxygen annealing process at varying temperatures.
• Evaluating sensor performance including response, baseline stability, repeatability, and recovery time.
• Conducting field tests at a sewage treatment plant.

Main Results:

• Increasing annealing temperature reduced DMDS gas response but maintained stable baseline resistance.
• The annealed sensor demonstrated a 34-fold improvement in gas repeatability and 20% faster recovery time compared to non-annealed MoO3.
• Field tests at a sewage treatment plant yielded clear DMDS responses comparable to standard gas cylinders.

Conclusions:

• Optimizing vacancy concentration through annealing is crucial for enhancing the reliability and performance of MoO3-based DMDS gas sensors.
• The developed sensor shows potential for practical odor monitoring systems, particularly in environments like sewage treatment plants.
• This study provides valuable insights for designing effective metal-oxide gas sensors for volatile organic compound detection.