Regulating Charge Distribution in Porphyrin‐Based Polymer for Achieving Photocatalytic CO2 Conversion to CH4 or C2H6

Abstract

The photocatalytic conversion of CO2 into products such as CH4 and C2H6 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 CO2 conversion to CH4 and C2H6 under the irradiation of light. Co active site is introduced to reduce the energy barrier and facilitate the charge transfer. The reaction pathway for C2H6 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 CO2 reduction performance and achieve the formation of C2 products under 300‐W Xe lamp irradiation.