Highly Selective and Flexible HCl Sensor Enabled by Ag₂O-Functionalized Graphene Micropatterns.

Area of Science:

• Materials Science
• Nanotechnology
• Chemical Sensing

Background:

• Graphene offers excellent properties for gas sensors but suffers from low selectivity and irreversible behavior.
• Existing functionalization methods for graphene sensors have not adequately addressed strong acid detection.
• Conventional acid sensors face limitations in power consumption, humidity stability, and long-term durability.

Purpose of the Study:

• To develop a highly selective and sensitive room-temperature sensor for hydrogen chloride (HCl) detection.
• To functionalize graphene with silver oxide (Ag2O) nanoparticles for enhanced gas sensing capabilities.
• To explore the potential of graphene-based sensors for strong acid detection in flexible electronics.

Main Methods:

• Fabrication of Ag2O-functionalized graphene micropatterns.
• Room-temperature gas sensing measurements for HCl detection.
• Density Functional Theory (DFT) calculations to investigate the interaction mechanism between Ag2O and HCl.

Main Results:

• Achieved unprecedented room-temperature HCl detection with ultra-high selectivity.
• Demonstrated an extremely low detection limit of 5.617 parts per trillion (ppt) for HCl.
• DFT calculations revealed strong Ag2O-HCl interaction due to charge depletion, enhancing HCl molecule attraction.

Conclusions:

• Ag2O-functionalized graphene presents a promising platform for highly selective and sensitive HCl sensing.
• Graphene's inherent properties, like Joule heating and acid resistance, improve sensor stability and reduce power consumption.
• This work advances graphene-based sensor technology for next-generation flexible electronics, particularly for strong acid detection.