Chemical Defect-Driven Response on Graphene-Based Chemiresistors for Sub-ppm Ammonia Detection.

Area of Science:

• Materials Science
• Nanotechnology
• Chemical Engineering

Background:

• Gas sensors are critical across various sectors, demanding high sensitivity, rapid response/recovery, low power, and cost-effectiveness.
• Graphene shows significant potential for gas sensing, but material functionalization is often necessary to enhance performance.

Purpose of the Study:

• To develop efficient and cost-effective gas sensors for ammonia detection.
• To explore a novel method for functionalizing graphene for improved sensing capabilities.
• To investigate the underlying mechanisms of graphene-based ammonia sensing.

Main Methods:

• Functionalization of graphene using diazonium chemistry with diverse functional groups.
• Fabrication and testing of gas sensors based on covalently modified graphene layers.
• Interpretation of experimental sensing data using theoretical calculations.

Main Results:

• An easy and efficient method for graphene functionalization via diazonium chemistry was established.
• Covalently modified graphene layers exhibited superior sensing capabilities for ammonia detection.
• Theoretical calculations confirmed that sensor response to ammonia is defect-driven.

Conclusions:

• The developed functionalization technique offers a pathway to highly sensitive and responsive graphene-based gas sensors.
• Defect engineering in graphene is a key factor for optimizing ammonia sensing performance.
• These findings support the practical design and implementation of advanced graphene sensors for real-world applications.