Photoinduced double charge accumulation in a molecular compound

Area of Science:

• Artificial photosynthesis
• Photochemistry
• Molecular electronics

Background:

• Photochemistry typically involves single electron transfer events.
• Artificial photosynthesis demands efficient multi-electron reactions.
• Achieving light-driven charge accumulation without sacrificial reagents is challenging.

Purpose of the Study:

• To develop a molecular compound capable of reversible multi-electron charge accumulation.
• To investigate efficient and sustainable light-driven multi-electron transfer.
• To advance research towards solar fuel production.

Main Methods:

• Design and synthesis of a molecular donor-photosensitizer-acceptor compound.
• Investigation of light absorption and subsequent charge accumulation.
• Characterization of photoproduct quantum yield, lifetime, and energy storage capacity.

Main Results:

• A novel molecular compound demonstrated reversible accumulation of two positive and two negative charges upon light absorption.
• The photoproduct formed with a 37% quantum yield.
• The system stored 3.0 eV of energy with a photoproduct lifetime exceeding 100 ns.

Conclusions:

• Structurally defined molecular compounds can efficiently perform light-driven multi-electron transfer.
• This approach offers a sustainable pathway for solar fuel generation.
• The findings provide fundamental insights for developing practical artificial photosynthesis systems.