Decoupled Artificial Photosynthesis via a Catalysis-Redox Coupled COF||BiVO4 Photoelectrochemical Device

Artificial photosynthesis is an attractive approach todirect fuelproduction from sunlight. However, the simultaneous O-2 evolutionreaction (OER) and CO2 reduction reaction (CDRR) presentchallenges for product separation and safety. Herein, we propose astrategy to temporally decouple artificial photosynthesis throughphotoelectrochemical energy storage. We utilized a covalent organicframework (DTCo-COF) with redox-active electron donors (-C-OHmoieties) and catalytically active electron acceptors (cobalt-porphyrin)to enable reversible -C-OH/-C O redoxreaction and redox-promoted CO2-to-CO photoreduction. Integratingthe COF photocathode with an OER photoanode in a photoelectrochemicaldevice allows the effective storage of OER-generated electrons andprotons by -C O groups. These stored charges can belater employed for CDRR while regenerating -C O to completethe loop, thus enabling on-demand and separate production of O-2 or solar fuels. Our work sets the stage for advancementsin decoupled artificial photosynthesis and the development of moreefficient solar fuel production technologies.