Regulating π‐Conjugation in sp <sup>2</sup> ‐Carbon‐Linked Covalent Organic Frameworks for Efficient Metal‐Free CO <sub>2</sub> Photoreduction with H <sub>2</sub> O
Lan Yang, Wenkai Yan, Na Yang, Guofeng Wang, Yingpu Bi, Chengcheng Tian, Honglai Liu, Xiang Zhu
Abstract
Abstract The development of sp 2 ‐carbon‐linked covalent organic frameworks (sp 2 c‐COFs) as artificial photocatalysts for solar‐driven conversion of CO 2 into chemical feedstock has captured growing attention, but catalytic performance has been significantly limited by their intrinsic organic linkages. Here, a simple, yet efficient approach is reported to improve the CO 2 photoreduction on metal‐free sp 2 c‐COFs by rationally regulating their intrinsic π‐conjugation. The incorporation of ethynyl groups into conjugated skeletons affords a significant improvement in π‐conjugation and facilitates the photogenerated charge separation and transfer, thereby boosting the CO 2 photoreduction in a solid‐gas mode with only water vapor and CO 2 . The resultant CO production rate reaches as high as 382.0 µmol g −1 h −1 , ranking at the top among all additive‐free CO 2 photoreduction catalysts. The simple modulation approach not only enables to achieve enhanced CO 2 reduction performance but also simultaneously gives a rise to extend the understanding of structure‐property relationship and offer new possibilities for the development of new π‐conjugated COF‐based artificial photocatalysts.