A cofacial metal-organic framework based photocathode for carbon dioxide reduction

Area of Science:

• Materials Science
• Photochemistry
• Electrochemistry

Background:

• Efficient solar energy harvesting is crucial for sustainable technologies.
• Metal-Organic Frameworks (MOFs) offer tunable properties for energy applications.
• CO2 reduction to CO is a key process for carbon utilization.

Purpose of the Study:

• To demonstrate the photocathode functionality of a novel MOF.
• To investigate the MOF's ability to reduce the overpotential for CO2 reduction.
• To explore the role of cofacial NDI ligands in photo- and electro-activity.

Main Methods:

• Synthesis and characterization of a novel MOF, [Cd(DPNDI)(TDC)].
• Electrochemical reduction to a mixed-valence state inducing Intervalence Charge Transfer (IVCT).
• Visible light irradiation and Density Functional Theory (DFT) calculations to study photoexcited states.

Main Results:

• The mixed-valence MOF exhibited through-space IVCT within cofacial DPNDI units.
• Visible light irradiation generated a stabilized DPNDI photoexcited radical monoanion state.
• This photoexcited state reduced a rhenium catalyst, lowering the overpotential for CO2 to CO conversion.

Conclusions:

• The novel MOF demonstrates efficient photocathode functionality for CO2 reduction.
• The study highlights the potential of cofacial MOFs in light-harvesting material design.
• This work opens new avenues for developing advanced materials for solar energy conversion.