Regulating Charge Distribution in Porphyrin‐Based Polymer for Achieving Photocatalytic CO 2 Conversion to CH 4 or C 2 H 6

Abstract The photocatalytic conversion of CO 2 into products such as CH 4 and C 2 H 6 poses a significant challenge due to the lengthy reaction steps and the high energy barrier involved. In this study, both benzothiadiazole (BTD) and hydroxyl groups (‐OH) are introduced into cobalt‐based polymerized porphyrinic network (PPN) through a C‐C coupling reaction. This modification of orbital energy levels that strengthens the ability of gain electrons and facilitates the charge transfer in PPN. Hydroxyl group largely enhances the ability for light response, while thiadiazole unit tunes the molecular orbital to proper energy level. By this way, BTD‐DBP‐PPN(Co) achieves the capability for CO 2 conversion to CH 4 and C 2 H 6 under the irradiation of light. Co active site is introduced to reduce the energy barrier and facilitate the charge transfer. The reaction pathway for C 2 H 6 production has been studied for further mechanism explanation. Overall, a series of cobalt‐based porphyrin centers with a donor–acceptor (D‐A) structure are designed and synthesized to enhance CO 2 reduction performance and achieve the formation of C 2 products under 300‐W Xe lamp irradiation.