DFT-Assisted Design of D–A Conjugated Polymers for Photocatalytic Reduction of Carbon Dioxide

Renewable-energy-driven CO2 transformation to chemicals and fuels is promising but still challenging. Herein, with the help of a density functional theory (DFT) analysis of molecular orbital energies, a series of electron donor–acceptor (D–A) conjugated organic polymers were designed and prepared by one-step Scholl coupling of polycyclic arenes and anthraquinone. The resultant polymers exhibit high efficiency in photocatalytic CO2 reduction with water vapor in the absence of any additional sacrificial reductant under visible light irradiation. In particular, the polymer from anthraquinone and triphenylamine could afford CO with a generation rate of 69.7 μmol g–1 h–1 and selectivity of >99.9%, which is superior to most metal-free and sacrificial reductant-free systems. Molecular orbital visualizations indicate that photocatalysts show clear charge separation under visible light stimulation. In addition, control experiments and contact angle tests demonstrated that the high selectivity toward CO may come from the intrinsic hydrophobicity of the photocatalysts. This work provides new insight into the DFT-assisted design of organic polymeric photocatalysts.