Fabricating MOF-GO Composites by Modulating Graphene Oxide Content to Achieve Superprotonic Conductivity

Area of Science:

• Materials Science
• Electrochemistry
• Nanotechnology

Background:

• Proton conductivity in materials is critical for alternative energy technologies.
• Metal-organic frameworks (MOFs) show potential but require conductivity enhancement.
• Graphene oxide (GO) integration offers a route to improve MOF properties.

Purpose of the Study:

• To synthesize and characterize MOF-GO composites for enhanced proton conductivity.
• To investigate the effect of GO content on the properties of Cr-MIL-101 MOF.
• To evaluate the potential of these composites in energy applications like PEMFCs.

Main Methods:

• In situ crystallization of Cr-MIL-101 MOF onto graphene oxide (GO) sheets.
• Fabrication of MIL-101/GO composites with varying GO concentrations (1%, 2%, 5%).
• Measurement of proton conductivity under varying temperature and humidity conditions.

Main Results:

• All synthesized MOF-GO composites demonstrated higher proton conductivity than pristine Cr-MIL-101 MOF.
• The MIL-101/GO(2%) composite exhibited the highest proton conductivity, reaching 0.105 S cm^-1 at 80 °C and 98% RH.
• Oxygen functional groups on GO enhanced the acidity and hydrophilicity, contributing to improved conductivity.

Conclusions:

• MOF-GO composites offer a promising strategy for developing advanced proton-conductive materials.
• The MIL-101/GO(2%) composite shows potential as an effective nanofiller for proton exchange membranes.
• These findings support the application of MOF-GO composites in proton exchange membrane fuel cells (PEMFCs) and other energy devices.