Porous-Organic-Polymer Rich Re Functional Units and Lewis Base Sites for Efficient CO2 Photoreduction

Photocatalytic reduction of CO2 into valuable chemicals or fuels is one of the promising solutions to mitigate climate changes. However, sound photocatalysts with sensitive responses to light, efficient enrichment and reduction of CO2 have not been well explored. Herein, we design and synthesize a porous organic polymer (POP), BTN-Re out of two key units, i.e. Re(bpy)(CO)3Cl (bpy = 2,2'-bipyridine) and melamine. Re(bpy)(CO)3Cl offers excellent CO2 reduction ability of functional units to BTN-Re, meanwhile, the abundant Lewis base sites brought in by melamine promote capture of CO2 contributes to the reduction of CO2. Steady-state fluorescence tests confirm that integrating Re(bpy)(CO)3Cl into BTN-Re skeletons efficiently inhibits electron-hole recombination. It is evident that BTN-Re exhibits an outstanding ability to photo-reduce CO2, with an average rate of 500.7 μmol·g-1·h-1 under visible light irradiation. This work provides a novel strategy for designing POPs-based materials as photoreduction catalyst to reduce CO2.