A Near-Isotropic Proton-Conducting Porous Graphene Oxide Membrane

Area of Science:

• Materials Science
• Electrochemistry
• Nanotechnology

Background:

• Graphene oxide (GO) membranes offer excellent properties for separators but suffer from anisotropic ion conduction.
• This anisotropy hinders through-plane conductivity, crucial for solid-state electrolytes in electrochemical devices.

Purpose of the Study:

• To enhance the through-plane proton conductivity of GO membranes.
• To reduce the anisotropic nature of GO membranes by introducing pores.
• To explore the application of modified GO membranes in alcohol fuel cell sensors.

Main Methods:

• Sonication-assisted Fenton reaction to create pores on GO nanosheets, forming porous GO (pGO).
• Characterization of pGO membrane anisotropy and proton conductivity.
• Fabrication and testing of an alcohol fuel cell sensor using pGO as the solid electrolyte.

Main Results:

• The pGO membrane exhibited near-isotropic behavior with a low degree of anisotropy (2.77).
• A 47% enhancement in through-plane proton conductivity was observed at 25 °C and 100% relative humidity compared to pristine GO.
• The membrane demonstrated excellent selectivity, linearity, and low ethanol detection limits (25 ppm) in an alcohol fuel cell sensor.

Conclusions:

• Pore formation via the sonication-assisted Fenton reaction effectively transforms anisotropic GO membranes into near-isotropic ion conductors.
• The developed pGO membranes show significant potential for improving solid-state electrolytes and sensing applications.
• The facile, scalable, and cost-effective method offers a promising route for advanced membrane development.