Crystalline Graphdiyne Nanosheets Produced at a Gas/Liquid or Liquid/Liquid Interface

Area of Science:

• Materials Science
• Organic Chemistry
• Nanotechnology

Background:

• Two-dimensional polymers, or bottom-up nanosheets, are ultrathin polymeric frameworks synthesized from atomic, ionic, or molecular components.
• Few existing synthetic 2D polymers utilize carbon-carbon bond formation, representing an underexplored area in materials chemistry.

Purpose of the Study:

• To develop a bottom-up synthesis for all-carbon, π-conjugated graphdiyne nanosheets.
• To investigate efficient synthesis protocols for creating high-quality graphdiyne materials.

Main Methods:

• A liquid/liquid interfacial protocol using hexaethynylbenzene and a copper catalyst.
• A gas/liquid interfacial synthesis by sprinkling hexaethynylbenzene onto an aqueous catalyst solution.

Main Results:

• The liquid/liquid method produced multilayer graphdiyne (24 nm thickness, >25 μm domain size) via alkyne-alkyne homocoupling.
• The gas/liquid method yielded superior single-crystalline graphdiyne nanosheets (3.0 nm thickness, 1.5 μm lateral size) with hexagonal domains and lower oxygenation.

Conclusions:

• The gas/liquid interfacial synthesis is a more effective method for producing high-quality, all-carbon graphdiyne nanosheets.
• This work establishes a new route for synthesizing π-conjugated 2D polymers with potential applications in advanced materials.