Engineering Ag₆ Cluster-Based Donor-Acceptor Heterojunctions Into Hydrogen-Bonded Organic Frameworks for...

Area of Science:

• Materials Science
• Nanotechnology
• Supramolecular Chemistry

Background:

• Atomically precise coinage metal nanoclusters exhibit unique optoelectronic properties but suffer from poor charge migration due to weak interactions.
• Hydrogen-bonded organic frameworks (HOFs) provide a method to create ordered crystalline materials from functional clusters, maintaining molecular isolation.

Purpose of the Study:

• To engineer the first coinage-metal-cluster-based donor-acceptor (D-A) heterojunction within a HOF.
• To investigate the structural and electronic properties of the Ag6-HOF for enhanced photocatalysis.

Main Methods:

• Synthesis of a silver-6 (Ag6) cluster donor and 4,4'-bipyridine (BPY) acceptor.
• Utilizing directional N-H···N hydrogen bonds for self-assembly into a crystalline Ag6-HOF.
• Photoelectrochemical studies and density functional theory (DFT) calculations.

Main Results:

• Formation of a crystalline Ag6-HOF with preserved Ag6 cluster integrity and hydrogen-bonded channels for charge transport.
• Identification of an S-scheme heterojunction with spatially separated HOMO (Ag6) and LUMO (BPY).
• Enhanced visible-light absorption and significantly boosted photocatalytic H2O2 production compared to individual components.

Conclusions:

• Hydrogen-bond-directed assembly is a versatile strategy for designing advanced cluster-based heterojunctional materials.
• The Ag6-HOF exhibits tunable electronic structures for improved photocatalytic performance.
• This approach offers a pathway to develop efficient photocatalysts for applications like H2O2 production.