Real-Time and Simultaneous Monitoring of NO, NO₂, and N₂O Using Substrate-Integrated Hollow Waveguides Coupled to a...

Area of Science:

• Environmental Science
• Analytical Chemistry
• Sensor Technology

Background:

• Nitrogen fertilizers and fossil fuel combustion release significant atmospheric nitrogen gases (NO, NO2, N2O).
• These gases contribute to air pollution, acid rain, and climate change.
• Effective monitoring requires compact, in situ sensor technology.

Purpose of the Study:

• To develop an innovative sensor platform for simultaneous, real-time quantification of NO, NO2, and N2O.
• To enable in situ monitoring of nitrogen gases in various environmental and industrial settings.

Main Methods:

• Combined a compact Fourier transform infrared (FT-IR) spectrometer with a substrate-integrated hollow waveguide (iHWG) gas cell.
• Developed a mid-infrared chemical sensor platform for gas analysis.

Main Results:

• Achieved limits of detection of 10 ppm for NO, 1 ppm for NO2, and 0.5 ppm for N2O.
• Demonstrated a linear concentration range suitable for vehicle exhaust analysis.
• The platform is adaptable for preconcentration or UV conversion modules and alternative laser sources.

Conclusions:

• The developed sensor platform provides a novel solution for simultaneous, in situ monitoring of key nitrogen gases.
• Its compact design and high sensitivity make it suitable for diverse applications, including vehicle emissions.
• Future adaptations could expand its utility for a wider range of nitrogen gas sensing scenarios.