Acid-Dependent Charge Transport in a Solution-Processed 2D Conductive Metal-Organic Framework

Area of Science:

• Materials Chemistry
• Solid-State Chemistry
• Nanotechnology

Background:

• Conductive metal-organic frameworks (MOFs) are challenging to develop due to difficulties in doping.
• Existing 2D MOFs with CuO4 metal nodes have limited electrical conductivity.

Purpose of the Study:

• To synthesize and characterize novel 2D conductive MOFs.
• To investigate a new doping strategy for MOFs.
• To develop solution-processable conductive MOF thin films.

Main Methods:

• Synthesis of 2D polycrystalline frameworks Cu3(HHTATP)2 using pendant amine-functionalized hexahydroxytriphenylene (HHTATP) linkers.
• Electrical conductivity measurements of the synthesized MOFs.
• Acid treatment to induce protonation and study conductivity changes.
• Spin-coating technique for fabricating large-area thin films.

Main Results:

• Achieved the highest electrical conductivity (1.21 S/cm) among 2D MOFs with CuO4 metal nodes.
• Demonstrated protonation-dependent conductivity increase upon acid treatment.
• Successfully fabricated large-area thin films via spin-coating.

Conclusions:

• Pendant amines on HHTATP linkers enable the development of highly conductive 2D MOFs.
• Acid-induced protonation offers an effective doping strategy for these MOFs.
• Solution-processable conductive MOF thin films can be fabricated using a simple spin-coating method.