Experimental Sensing and Density Functional Theory Study of H₂S and SOF₂ Adsorption on Au-Modified Graphene

Area of Science:

• Materials Science
• Chemical Sensing
• Nanotechnology

Background:

• Electrical equipment insulation relies on sulfur hexafluoride (SF₆) gas.
• Insulation faults produce characteristic decomposed gases like hydrogen sulfide (H₂S) and sulfur oxyfluoride (SOF₂).
• Accurate detection of these gases is crucial for assessing equipment integrity.

Purpose of the Study:

• To develop a selective gas sensor for SF₆ decomposition products.
• To investigate the sensing performance of gold nanoparticle-modified graphene films (Au-GrF).
• To elucidate the adsorption mechanisms using first-principles calculations.

Main Methods:

• Fabrication of graphene films (GrF) modified with gold (Au) nanoparticles.
• Gas sensing experiments at room temperature to detect H₂S and SOF₂.
• First-principles calculations (density of states, Mulliken population analysis) to simulate gas-GrF interactions.

Main Results:

• Au-GrF exhibited opposite resistance responses to H₂S and SOF₂.
• Demonstrated selectivity for H₂S and SOF₂ detection.
• Calculations confirmed charge transfer in Au-GrF chemisorption, explaining observed responses.

Conclusions:

• Au-modified GrF is a promising material for selective H₂S and SOF₂ detection.
• The study provides insights into graphene modulation for gas sensor design.
• This work contributes to improved methods for electrical equipment insulation assessment.