Aryl fluoride functionalized graphene oxides for excellent room temperature ammonia sensitivity/selectivity

Area of Science:

• Materials Science
• Chemical Engineering
• Sensor Technology

Background:

• Graphene oxide (GO) is a promising material for gas sensing applications.
• Developing highly sensitive and selective ammonia sensors is crucial for environmental monitoring and industrial safety.
• Traditional GO-based sensors often require high operating temperatures or exhibit limited sensitivity.

Purpose of the Study:

• To achieve covalent functionalization of graphene oxide (GO) using "click" chemistry.
• To enhance the sensitivity and performance of GO-based ammonia sensors.
• To investigate the ammonia sensing properties of functionalized GO at room temperature.

Main Methods:

• Covalent functionalization of GO with azide moieties.
• Click coupling of aryl propargyl ether derivatives to GO.
• Characterization of functionalized GO using various spectroscopic and thermal techniques (NMR, XRD, SEM, FT-IR, Raman, UV-Vis, TGA, DSC).
• Evaluation of ammonia sensing performance at room temperature.

Main Results:

• Functionalized GO (GO-Ar) demonstrated excellent room temperature ammonia sensing properties.
• GO functionalized with 2,3-difluoro (GO-Ar2) and 2,3,4-trifluoro (GO-Ar3) aryl propargyl ethers showed superior sensing.
• GO-Ar2 and GO-Ar3 exhibited response/recovery times of 63%/~90% and 60%/100% at 20 ppm ammonia, respectively.
• GO-Ar3 displayed high sensitivity towards ammonia in the 20-100 ppm range.
• Computational studies confirmed high adsorption energy, supporting the enhanced sensitivity.

Conclusions:

• Covalent functionalization of GO via "click" reaction significantly enhances ammonia sensing capabilities.
• Fluorinated aryl propargyl ether functionalized GO (GO-Ar2 and GO-Ar3) are highly effective for room temperature ammonia detection.
• The developed functionalized GO materials show great potential for sensitive and efficient ammonia sensing applications.