Mixed-Blocks-Driving Nickel-Porphyrin Covalent Organic Polymers for Photocatalytic Syngas Production from CO with Fine Selectivity.

CO photoconversion to syngas with superb selectivity is a splendid and bright option to achieve environmental improvement, energy substitution, and industrial needs. Herein, a series of Ni-porphyrin covalent organic polymers (COPs) interspersed with furan and thiophene using a mixed-blocks-engineering strategy, named as OS-Ni COPs ( and refer to the relative amounts of furan and thiophene blocks, respectively), are synthesized for photocatalytic CO-to-syngas. Ni-coordinated porphyrin cores prefer to act as mediators of CO-to-CO photoconversion because of the higher adsorption capacity of CO. Ni-free porphyrins work mainly as active sites of H photoevolution. Furthermore, introducing different amounts of furan and thiophene modulates jointly the electronic structure of Ni-porphyrin COPs and optimizes the conduction band alignment. The above controllable variables achieve a wonderful syngas (CO/H) ratio range from 2:1.06 to 1:1.04 for the Fischer-Tropsch process within common industrial reactions. Notably, the COP of the OS-Ni COPs exhibits excellent photocatalytic CO-to-syngas activity under visible light, with a syngas yield of 8442.5 μmol g h (CO/H = 1:1.02) and an apparent quantum efficiency (AQE) of 1.92% at 450 nm. This strategy would provide a significance path to design functional and efficient organic semiconductors.