Reversible CO₂ Capture and On-Demand Release by an Acidity-Matched Organic Photoswitch

Area of Science:

• Environmental Chemistry
• Photochemistry
• Materials Science

Background:

• Carbon capture technologies are vital for climate change mitigation.
• Current methods face high energy costs for sorbent regeneration.
• Solar-driven CO2 capture offers a sustainable alternative.

Purpose of the Study:

• To develop a photochemically driven system for CO2 capture and release.
• To investigate the thermodynamic requirements for solar-powered CO2 capture.
• To explore photoinduced metastable states for modulating CO2-derived species stability.

Main Methods:

• Utilized a photoswitchable organic molecule with tunable acidity.
• Investigated dark-light cycles for CO2 capture and release.
• Employed transient absorption spectroscopy to study excited-state dynamics.

Main Results:

• Demonstrated repeated, near-stoichiometric CO2 capture and release.
• Identified CO2-derived species as a solvent-separated ion pair.
• Characterized excited-state dynamics influencing photorelease efficiency.

Conclusions:

• Established thermodynamic and kinetic principles for solar-powered CO2 capture.
• Developed a viable model for solar-driven negative emission technologies.
• Highlighted the potential of photoswitchable molecules in sustainable carbon management.