Enhanced Nitrogen Dioxide Detection Using Resistive Graphene-Based Electronic Sensors Modified with Polymers of...

Area of Science:

• Materials Science
• Chemical Sensing
• Nanotechnology

Background:

• Graphene-based sensors offer promise for gas detection due to their unique electronic properties.
• Enhancing graphene's sensitivity and selectivity for specific gases remains a key challenge.
• Polymers of intrinsic microporosity (PIMs) present a novel material class for modifying sensor surfaces.

Purpose of the Study:

• To fabricate and evaluate graphene pixel array sensors coated with PIMs (PIM-1, PIM-EA-TB) and Matrimid for nitrogen dioxide (NO2) detection.
• To assess the impact of these polymer coatings on gas sensing performance, including sensitivity, response time, and selectivity.
• To explore the potential of PIM-coated graphene sensors for real-time environmental monitoring of toxic gases.

Main Methods:

• Fabrication of 3x3 graphene pixel array sensors.
• Coating graphene surfaces with thin films (9-11 nm) of PIM-1, PIM-EA-TB, and Matrimid.
• Real-time gas sensing evaluation with varying NO2 concentrations (1-50 ppm).
• Selectivity testing against ammonia (NH3), nitric oxide (NO), methane (CH4), and carbon dioxide (CO2).

Main Results:

• Polymer coatings significantly enhanced NO2 sensing performance, with responses up to -25.7% compared to -10.8% for bare graphene.
• Reduced response times by 56 s and rapid recovery times (114-153 s) were observed.
• High selectivity for NO2 with minimal cross-sensitivity to other tested gases.
• Achieved limits of detection in the low parts per billion range, with PIM-EA-TB reaching 0.7 ppb.

Conclusions:

• PIM-coated graphene sensors demonstrate superior sensitivity and selectivity for NO2 detection.
• These sensors show potential for cost-effective, real-time environmental monitoring of toxic gases.
• PIMs are effective in enhancing the performance of graphene-based gas sensors, paving the way for advanced detection systems.