Triangular-Tessellated Charge Transfer Cocrystals Derived from Melamine with Enhanced Photocatalytic Performance.

Area of Science:

• Materials Science
• Photocatalysis
• Organic Semiconductors

Background:

• Charge transfer (CT) cocrystals are promising for advanced functional materials.
• Controlling CT interactions in cocrystals via structural design and synthesis is challenging.

Purpose of the Study:

• To demonstrate a tessellation-based strategy for modulating CT strength in melamine-derived cocrystals.
• To investigate the structure-property relationships in MMC-12 and MMC-31 cocrystals.

Main Methods:

• Synthesis of melamine-derived cocrystals (MMC-12 and MMC-31).
• Transient absorption (TA) spectroscopy to probe excited-state dynamics.
• Theoretical simulations to understand electronic structure and charge transfer.

Main Results:

• MMC-31 exhibits enhanced CT interactions with rapid electron transfer from melamine to melem.
• Formation of weakly bound CT excitons in MMC-31 that readily dissociate into free carriers.
• 18-fold enhancement in H2O2 production and 12-fold enhancement in H2 evolution using MMC-31 compared to melem.

Conclusions:

• Geometric tessellation is a viable design principle for tuning CT strength in organic materials.
• Melamine-derived cocrystals show potential as high-performance photocatalysts.
• The developed strategy offers a pathway for designing advanced organic semiconductors and photocatalysts.