Titanium nitride sensor for selective NO₂ detection.

Area of Science:

• Materials Science
• Environmental Science
• Chemical Engineering

Background:

• Nitrogen dioxide (NO2) is a significant air pollutant from fossil fuel combustion, impacting ecological and human health.
• Existing NO2 detection methods suffer from poor stability and selectivity, limiting their effectiveness.
• There is a critical need for advanced, reliable, and cost-effective NO2 monitoring solutions.

Purpose of the Study:

• To develop a novel transition metal nitride-based sensor for highly selective and stable NO2 detection.
• To investigate the performance of titanium nitride (TiNx) nanoparticles with engineered nitrogen vacancies for gas sensing.
• To demonstrate a viable alternative to precious metal-based sensors for environmental NO2 monitoring.

Main Methods:

• Synthesis of highly active titanium nitride (TiNx) nanoparticles with large surface area and high nitrogen vacancy concentration.
• Fabrication and testing of the TiNx nanoparticle-based gas sensor.
• Evaluation of sensor selectivity against interfering gases like nitric oxide (NO) and assessment of long-term stability.

Main Results:

• The developed TiNx sensor exhibited exceptional selectivity for NO2, with a sensitivity 30 times greater than that for NO.
• The sensor demonstrated remarkable stability, maintaining performance over a 6-month period.
• Unlike the active TiNx nanoparticles, a commercial titanium nitride (TiN) sample showed no gas sensing activity.

Conclusions:

• Highly active TiNx nanoparticles with engineered nitrogen vacancies are crucial for high-performance NO2 sensing.
• Transition metal nitride sensors offer a promising, cost-effective, and stable alternative to precious metal-based technologies for NO2 detection.
• This technology is scalable and suitable for widespread environmental monitoring applications.