Insights into Decoupled Solar Energy Conversion and Charge Storage in a 2D Covalent Organic Framework for Solar...

Area of Science:

• Materials Science
• Energy Storage
• Photochemistry

Background:

• Decoupling solar energy conversion and storage is crucial for off-grid applications.
• Existing materials often face limitations in charge stabilization and storage capacity.

Purpose of the Study:

• To develop a single material capable of both solar energy conversion and storage.
• To investigate the charge stabilization mechanism in a novel NDI-COF.
• To evaluate the solar battery performance of the NDI-COF.

Main Methods:

• Synthesis of a two-dimensional naphthalenediimide (NDI)-based covalent organic framework (COF).
• Utilizing optical spectroscopy, (photo)electrochemical measurements, and density functional theory (DFT) simulations.
• Investigating the effect of different solvents, particularly water, on charge stabilization.

Main Results:

• The NDI-COF demonstrated remarkable solar battery performance as a photoanode.
• Light-induced radicals were stabilized within the framework for extended periods (over 48 hours in water).
• Water was identified as an optimal solvent for stabilizing photoinduced radicals via dielectric screening and proton exchange.

Conclusions:

• The NDI-COF offers a highly tunable, nanoporous platform for optoionic charge storage.
• This material surpasses conventional materials like MOFs and metal oxides in charge storage capacity.
• The findings open new avenues for designing materials for direct solar energy storage, addressing intermittency issues.