ZnO-Loaded Graphene for NO₂ Gas Sensing

Area of Science:

• Materials Science
• Nanotechnology
• Chemical Sensing

Background:

• Graphene-based sensors are promising for gas detection.
• Zinc oxide (ZnO) nanoparticles can enhance sensor performance.
• Nitrogen dioxide (NO2) is a harmful pollutant requiring sensitive detection methods.

Purpose of the Study:

• To investigate the effect of ZnO nanoparticle decoration on graphene for NO2 detection.
• To compare the performance of graphene sensors with different ZnO loadings (5 wt.% and 20 wt.%).
• To evaluate sensor performance under varying humidity levels and assess selectivity.

Main Methods:

• Preparation of graphene decorated with ZnO nanoparticles at 5 wt.% (G95/5) and 20 wt.% (G80/20).
• Testing sensor response to NO2 at room temperature under dry and humid conditions.
• Evaluating sensor selectivity against other common gases.

Main Results:

• The G95/5 sensor demonstrated superior performance in detecting low concentrations of NO2 compared to G80/20.
• The G95/5 sensor exhibited an eight-fold increase in NO2 sensitivity at 70% relative humidity compared to dry conditions.
• The sensor showed significant selectivity towards NO2 over other tested gases.

Conclusions:

• Graphene decorated with 5 wt.% ZnO nanoparticles is an effective material for NO2 sensing.
• Ambient humidity significantly enhances the NO2 sensing performance of the ZnO-decorated graphene.
• The developed sensor offers high selectivity for NO2 detection.