Abstract

Solar-driven photocatalytic reaction offer practical opportunities for producing value-added or fine chemicals by converting renewable solar energy into chemical energy. Organic polymeric materials, composed of organic chromophores with strong light absorption, have been widely employed as heterogeneous photocatalysts in the artificial photosynthetic manner. In this study,

we report covalent organic polymeric photocatalysts (COPs) consisting of two light-active units,

which can guide directional photoinduced charge transfers operated in natural system. The newly-

developed photocatalyst, coated into the thin film, was prepared as a reusable platform and applied

to the multi-functional catalytic processes for the light-driven CO 2 reduction reaction and multicomponent Biginelli condensation. According to the catalytic test based on the artificial photosynthesis, the COPs-coated film exhibited an efficient regeneration of NADH cofactor acting as an electron mediator with 67.96 %. The regenerated NADH facilitated the photoinduced electron transport from the photocatalyst to the catalytic center, contributing to an excellent conversion of CO 2 with the methanol production of 19.27 μmol. In the light-driven Biginelli reaction, the COPs-coated film showed high conversion efficiency and turnover frequency for producing various 3,4-dihydropyrimidine compounds. The systematic mechanistic studies based on time-resolved spectroscopies and DFT calculations revealed that the long-lived charge separation state in the photocatalyst plays a critical role in the photoinduced electron transport.

This study demonstrates the potential of COPs for the multi-functional catalytic reactions and

provide chemical insights into the photoinduced electronic dynamics associated with the macroscopic catalytic efficiency.