Electronic Transmission Channels Promoting Charge Separation of Conjugated Polymers for Photocatalytic CO ₂ Reduction with Controllable Selectivity

Abstract

Conjugated polymers (CPs) represent a promising platform for photocatalytic CO₂ fixation owing to their suitable band structures that meet the requirements of the reduction potential of CO₂ to value-added fuels. However, the photocatalytic performance of CPs is rather restrained by the low charge transfer efficiency. Herein, we rationally designed three CPs with a more delocalized electronic transmission channel and planar molecular structure, which are regarded to evidently reduce the exciton binding energy (E_b ) and accelerate the internal charge transfer process. Besides, the assembly of suitable electron-output "tentacles" and cocatalysts on the surface of CPs could effectively facilitate interfacial electron delivery. Accordingly, the optimal P-2CN exhibits an apparent quantum yield of 4.6 % at 420 nm for photocatalytic CO₂ to CO. Further adjusting the amounts of cyano groups and cocatalysts, the CO selectivity could be obtained in the range of 0-80.5 %.