Integration of Enzymes and Photosensitizers in a Hierarchical Mesoporous Metal-Organic Framework for Light-Driven CO₂...

Area of Science:

• Biotechnology
• Materials Science
• Renewable Energy

Background:

• Enzyme stabilization in non-native environments is crucial for biocatalysis.
• Synthetic supports and encapsulation enhance enzyme stability and reactivity.
• Cascade reactions are essential for processes like light-driven carbon dioxide reduction.

Purpose of the Study:

• To develop a semi-artificial system for converting carbon dioxide to formic acid using white light.
• To utilize an immobilized enzyme within a light-harvesting scaffold for efficient solar energy conversion.
• To demonstrate a feasible pathway for solar-driven carbon fixation.

Main Methods:

• Immobilization of formate dehydrogenase enzyme in a light-harvesting scaffold.
• Anchoring of an electron-mediator, Cp*Rh(2,2'-bipyridyl-5,5'-dicarboxylic acid)Cl, to the metal-organic framework NU-1006.
• Irradiation with white light to induce photo-induced electron transfer and coenzyme reduction.

Main Results:

• Ultrafast photo-induced electron transfer facilitated by the anchored electron-mediator.
• Efficient reduction of nicotinamide adenine dinucleotide (coenzyme) at a rate of approximately 28 mM·h⁻¹.
• Selective generation of formic acid from carbon dioxide by the immobilized enzyme with a high turnover frequency of approximately 865 h⁻¹ over 24 hours.

Conclusions:

• The developed semi-artificial system demonstrates a viable route for solar-driven carbon fixation.
• Enzyme immobilization within light-harvesting scaffolds enhances catalytic efficiency for CO2 conversion.
• This research provides a promising pathway for alternative energy generation through artificial photosynthesis.