Porous organic polymers containing organic photosensitizers and metal–terpyridine molecules for efficient aqueous CO₂ photoreduction

The development of photocatalysts with high efficiency and good selectivity under mild conditions, particularly in 100% aqueous medium, represents a critical avenue for the resourceful utilization of CO₂. In this work, 1,2,3,5-tetrakis(carbazol-9-yl)-4,6-dicyanobenzene and 10-(4-([2,2':6',2''-terpyridin]-4'-yl)phenyl)-10<i>H</i>-phenothiazine were employed as monomers to synthesize three porous organic polymers (denoted as SFOP, NiOP, and ZnOP). These amorphous polymers were applied for the photoreduction of CO₂ to CO in the absence of organic solvent. Compared to the negligible CO generation of monomers, these polymers are all effective in aqueous CO₂ photoreduction. Additionally, NiOP exhibited the highest CO yield (731.3 μmol g^-1) and selectivity (94.6%) due to a more efficient electron-transfer process. These results demonstrated that regulating metals in porous organic polymers enables the optimization of their catalytic performance.