Functionalized Reduced Graphene Oxide Thin Films for Ultrahigh CO₂ Gas Sensing Performance at Room Temperature

Area of Science:

• Materials Science
• Chemical Engineering
• Environmental Science

Background:

• Growing demand for carbon dioxide (CO2) gas detection, particularly at room temperature (RT), presents significant challenges.
• Graphene-based materials show promise for RT gas sensing due to their high surface area and electrical conductivity.

Purpose of the Study:

• To develop highly edge-functionalized chemically synthesized reduced graphene oxide (rGO) thin films for fast CO2 gas detection at room temperature.
• To optimize rGO synthesis for enhanced CO2 sorption and sensing performance.

Main Methods:

• Reduced graphene oxide (rGO) synthesized using ascorbic acid (AA) as a reducing agent.
• Three rGO concentrations (AArGO25, AArGO50, AArGO100) prepared using varying AA concentrations.
• Thin films characterized using FTIR, XRD, Raman, XPS, TEM, SEM, and four-point probe measurements.

Main Results:

• The AArGO25 sample exhibited the highest edge functionality and a conductivity of ~1389 S/cm.
• The AArGO25 gas sensor demonstrated fast response (~26 s) and recovery (~10 s) times for 500 ppm CO2 at RT.
• High sensitivity (~50 Hz/µg) and good repeatability were observed for CO2 detection.

Conclusions:

• Highly edge-functionalized rGO thin films are effective for rapid CO2 gas sensing at room temperature.
• The developed AArGO25 sensor shows potential for applications in enhanced oil recovery, industrial safety, and domestic safety.