Highly Sensitive and Selective SnO₂-Gr Sensor Photoactivated for Detection of Low NO₂ Concentrations at Room...

Area of Science:

• Materials Science
• Nanotechnology
• Environmental Science

Background:

• Accurate detection of nitrogen dioxide (NO2) is crucial for environmental monitoring and air quality control.
• Developing sensitive and selective gas sensors for low pollutant concentrations remains a challenge.

Purpose of the Study:

• To develop and characterize chemical nanosensors for detecting low NO2 concentrations.
• To investigate the effect of graphene decoration on tin dioxide nanoparticles for enhanced sensor performance.
• To evaluate sensor selectivity and performance in humid conditions and complex gas mixtures.

Main Methods:

• Fabrication of sensitive layers using tin dioxide and graphene-decorated tin dioxide nanoparticles via drop casting.
• Surface morphology and elemental composition analysis using Scanning Electron Microscopy/Energy Dispersive X-ray (SEM/EDX).
• Photoactivation of sensors for room temperature detection and evaluation of sensor response to NO2, CO, and CH4 under varying humidity levels.

Main Results:

• Nanosensors successfully detected ultra-low NO2 concentrations (100 ppb) at room temperature after photoactivation.
• Graphene incorporation significantly improved sensor sensitivity and selectivity towards NO2, with minimal cross-response to CO and CH4.
• The graphene-decorated sensor demonstrated high selectivity and robust performance in complex, humid atmospheres, showing significant responses to NO2 even in the presence of other gases.

Conclusions:

• Graphene-decorated tin dioxide nanosensors offer a promising solution for sensitive and selective detection of low NO2 concentrations.
• The developed sensors exhibit excellent performance under ambient conditions, including humidity and the presence of interfering gases.
• The findings highlight the potential of these nanosensors for real-time environmental monitoring applications.