Graphene oxide nanosheet with high proton conductivity

Area of Science:

• Materials Science
• Electrochemistry
• Nanotechnology

Background:

• Graphene oxide (GO) is typically an electronic insulator.
• Proton conductivity in materials is crucial for energy applications like fuel cells.

Purpose of the Study:

• To measure and compare the proton conductivity of graphite oxide (GO'), graphene oxide/proton hybrid (GO-H), and graphene oxide (GO) nanosheets.
• To investigate the potential of graphene oxide as a proton-conductive material.

Main Methods:

• Measurement of proton conductivity for GO', GO-H, and GO at 100% humidity.
• Analysis of the role of functional groups and adsorbed water in proton transport.

Main Results:

• Graphene oxide (GO) demonstrated exceptionally high proton conductivity (∼10⁻² S cm⁻¹).
• Graphite oxide (GO') and graphene oxide/proton hybrid (GO-H) showed significantly lower conductivities (∼10⁻⁴ and ∼10⁻⁵ S cm⁻¹, respectively).
• Proton conduction in GO is facilitated by hydrophilic functional groups and hydrogen-bonded water networks.

Conclusions:

• Graphene oxide exhibits superionic proton conductivity, reversing the expected trend for insulating materials.
• GO-based materials show promise for developing two-dimensional proton-conductive applications.
• Potential applications include fuel cells, sensors, and other electrochemical devices.