Mimicking Natural Photosynthesis: Sculpting Sunlight into Solar Fuels via a Sustained Photo-Enzymatic BT-NCOF Catalytic System

Abstract

The photocatalytic reduction of carbon dioxide into energy rich compounds has garnered much attention. Although, it is still a challenge to convert CO2 into value added chemicals by utilizing solar energy. This work reports, Benzene-1,3,5-tricarbaldehyde (B) coupled with multi-amine linkers (4,4',4''-(benzene-1,3,5-triyltris(ethyne-2,1-diyl))trianiline (T)) as a nitrogen-rich covalent organic framework (BT-NCOFs). Affording BT-NCOF as a photocatalyst with highly ordered channels and abundant co-ordination active sites for small molecules activations. Under solar light irradiation, BT-NCOF acts as an efficient heterogeneous photosystem, utilizing their extended conjugation to solar photons and drive selective reduction of CO2 to formic acid while simultaneously promoting NADH regeneration. The optimized BT-NCOF delivers remarkable solar to chemical conversion achieving NADH regeneration with a yield of 60.34% and a formic acid yield of 157.56 μmol. This study demonstrates that nitrogen rich BT-NCOF can blended light harvesting, charge separation, and catalytic functions within a single modular scaffold, offering a robust platform for artificial photosynthesis and sustainable CO2 sculpting into solar fuels.