Molecular Ir-Based Coordination Compound Grafted onto Covalent Organic Framework for Efficient Photocatalytic H₂...

Area of Science:

• Materials Science
• Catalysis
• Renewable Energy

Background:

• Reducing pollution and developing clean energy storage necessitates efficient photocatalytic hydrogen evolution (PHE).
• Improving solar conversion efficiency requires enhanced photocarrier separation and transport through advanced material design.

Purpose of the Study:

• To develop a stable hydrogen evolution photocatalyst using a molecular-level design strategy.
• To introduce molecular-scale Iridium (Ir) active sites onto TpPa-COFs (triformylphloroglucinol phenylenediamine covalent organic frameworks) via coordination bonds.

Main Methods:

• Synthesized TpPa-COFs and introduced Ir active sites.
• Characterized the material using Fourier transform infrared spectroscopy (FT-IR), X-ray photoelectron spectroscopy (XPS), and transmission electron microscopy (TEM).
• Evaluated photocatalytic hydrogen evolution rates and apparent quantum yield (AQY) under visible-light irradiation.

Main Results:

• Structural integrity of TpPa-COFs and the presence of Ir were confirmed.
• The absorption edge of Ir-modified TpPa-COFs was extended to 750 nm.
• The TpPa-COF + M1 catalyst achieved a high H2 evolution rate of 662 µmol/h (10 mg catalyst) with an AQY of 4.8% at 470 nm.

Conclusions:

• Molecular-level design of photocatalysts effectively enhances performance and reduces costs.
• This strategy provides a pathway for designing efficient photocatalysts for hydrogen production.
• The developed Ir-based TpPa-COF material shows significant potential for photocatalytic applications.