Carbazolic Conjugated Organic Polymers for Visible-Light-Driven CO Photoreduction with H O to CO with High Efficiency and Selectivity.

Visible-light-driven CO photoreduction with H O to value-added chemicals in high efficiency and selectivity is significant but challenging. Herein, a series of carbazolic conjugated organic polymers (CB-COPs) with electron donor-acceptor (D-A) structures were prepared, which showed high efficiency for visible-light-driven photocatalytic reduction of CO with H O in a solid-gas mode, affording CO as the exclusive carbonaceous product. Especially, CB-COP-mpd derived from 3,5-di(9H-carbazol-9-yl)pyridine exhibited the highest CO evolution rate up to 191.46 μmol g  h with a selectivity of 100 %. Mechanism studies showed that carbazolyl is a promising electron donor candidate for constructing CB-COPs with D-A structures, capable of improving the catalytic efficiency and suppressing H generation. The acceptor building block with excessive electron withdrawing capability was favorable to H O adsorption, thus resulting in the generation of H . This work provides new insights for designing COPs photocatalysts for CO photocatalytic reduction.