Molecular-based porous polymers with precise sites for photoreduction of carbon dioxide

Photocatalytic CO2 reduction reaction (CO2RR) is one of the promising strategies for sustainably producing solar fuels. The precise identification of catalytic sites and the enhancement of photocatalytic CO2 conversion is imperative yet quite challenging. This critical review summarizes recent advances in porous photo-responsive polymers, including COFs (covalent organic frameworks), CTFs (covalent triazine frameworks), and CMPs (conjugated microporous polymers), those can be rationally designed from the molecular level for visible-light-driven photocatalytic CO2 reduction. Additionally, special emphasis is placed on how the well-defined active sites on these polymers can influence their properties and photocatalytic performance. The precise regulation and control of microenvironments and electronic properties of metal active centers are crucial for boosting catalytic efficiency and selectivity, as well as for the design of better photocatalysts for CO2 reduction.