Anchoring Redox Mediator on COFs for Efficient Solar to Hydrogen Conversion

Area of Science:

• Materials Science
• Photocatalysis
• Renewable Energy

Background:

• Z-scheme heterojunctions are crucial for photocatalytic hydrogen production.
• Carrier recombination and mediator instability limit their efficiency.
• Existing redox mediators in solution lack stability and efficient electron transport.

Purpose of the Study:

• To develop a stable and efficient Fe-coordinated 2D Z-scheme heterojunction for photocatalytic hydrogen production.
• To overcome the limitations of traditional indirect Z-scheme systems.
• To enhance charge migration, stability, and catalytic activity.

Main Methods:

• Fabrication of a Fe-coordinated 2D Z-scheme heterojunction using TpPa-1-COF (TP1C) and Bi2WO6 (BWO).
• Characterization using extended X-ray absorption fine structure (EXAFS) and electrochemical tests.
• Evaluation of photocatalytic hydrogen production rates.

Main Results:

• The Fe mediator is firmly anchored on the COF skeleton, ensuring enhanced recyclability and stability.
• The 2D Z-scheme heterojunction provides abundant active sites and retains high redox properties.
• The 25% BWO/Fe/TP1C composite achieved a hydrogen production rate of 6.31 mmol·g−1·h−1, significantly outperforming pure COFs and BWO/TP1C.

Conclusions:

• The novel Fe-coordinated 2D Z-scheme heterojunction offers a stable and efficient platform for photocatalytic hydrogen production.
• Anchoring redox mediators on COF skeletons is a promising strategy to enhance photocatalyst performance.
• This work presents a new pathway for advancing COF-based materials in renewable energy applications.