Tuning Electronic and Proton Transfer Properties on Amino-Functionalized Co-Based MOF for Efficient Photocatalytic...

Area of Science:

• Materials Science
• Catalysis
• Renewable Energy

Background:

• Photocatalytic water splitting is a key technology for sustainable hydrogen (H₂) production.
• Metal-organic frameworks (MOFs) are promising materials for photocatalysis, but their efficiency needs improvement.
• The role of functional groups, like amino groups, in MOFs for photocatalysis is an active area of research.

Purpose of the Study:

• To investigate the dual role of amino substituents in azolate/cobalt-based MOFs for enhanced photocatalytic water splitting.
• To evaluate the performance of the amino-functionalized Co-MOF as a hydrogen evolution cocatalyst.
• To compare the efficiency of the developed Co-MOF with benchmark materials like platinum (Pt) and titanium dioxide (TiO₂).

Main Methods:

• Synthesis of an amino-functionalized azolate/cobalt-based metal-organic framework (MOF).
• Photocatalytic water splitting experiments using the Co-MOF with fluorescein (photosensitizer) and triethylamine (sacrificial agent).
• Characterization of the MOF's structure and properties, including the role of the amino group.

Main Results:

• The amino substituent in the Co-MOF demonstrated a dual role: acting as an electron donor and providing hydrogen-hopping sites.
• This dual functionality significantly enhanced the electron availability at active Co sites and facilitated proton diffusion.
• The amino-functionalized Co-MOF achieved a high H₂ production rate of 27 mmol g^-1 over 4 hours, outperforming Pt and TiO₂ cocatalysts.

Conclusions:

• Amino-functionalized Co-MOFs offer a highly efficient pathway for photocatalytic hydrogen production.
• The identified dual role of the amino group provides a new strategy for designing advanced MOF cocatalysts.
• This research contributes to the development of sustainable and cost-effective hydrogen generation technologies.