Efficient Crystallization of Conjugated Microporous Polymers to Boost Photocatalytic CO₂ Reduction

ABSTRACT The use of conjugated microporous polymers (CMPs) in photocatalytic CO₂ reduction (CO₂RR), leveraging solar energy and water to generate carbon‐based products, is attracting considerable attention. However, the amorphous nature of most CMPs poses challenges for effective charge carrier separation, limiting their application in CO₂RR. In this study, we introduce an innovative approach utilizing donor π‐skeleton engineering to enhance skeleton coplanarity, thereby achieving highly crystalline CMPs. Advanced femtosecond transient absorption and temperature‐dependent photoluminescence analyses reveal efficient exciton dissociation into free charge carriers that actively engage in surface reactions. Complementary theoretical calculations demonstrate that our highly crystalline CMP (Py‐TDO) not only greatly improves the separation and transfer of photoexcited charge carriers but also introduces additional charge transport pathways via intermolecular π–π stacking. Py‐TDO exhibits outstanding photocatalytic CO₂ reduction capabilities, achieving a remarkable CO generation rate of 223.97 μmol g⁻¹ h⁻¹ without the addition of chemical scavengers. This work lays pioneering groundwork for the development of novel highly crystalline materials, advancing the field of solar‐driven energy conversion.