| Abstrakt: |
In photocatalytic CO2reduction for solar fuel production, selectivity and efficiency are crucial. Here, we report the design and synthesis of a donor–acceptor imine-based porous organic polymer (POP) Tpa-Phendaand a metallo-porous organic polymer (M-POP) Tpa-Phenda-Ru, by reacting tris(4-formylphenyl)amine (Tpa) and Phenda/[Ru(Phenda)(bpy)2]2+(Phenda = 4,4′-(1,10-phenanthroline-3,8-diyl)dianiline; bpy = 2,2′-bipyridine) using acid-catalyzed Schiff base condensation reaction under solvothermal conditions. Here, the donor–acceptor dyads in both polymers harvested the visible light and transferred the photoexcited electrons to the active catalytic center, which is elucidated through in situUV–vis spectroscopy. Both Tpa-Phendaand Tpa-Phenda-Ruproduced CO in the acetonitrile–water medium using 1-benzyl-1,4-dihydronicotinamide (BNAH) and triethylamine (TEA) as sacrificial electron donors. Tpa-Phendaand Tpa-Phenda-Ruproduced 0.92 and 9.77 mmol g–1of CO, respectively. Tpa-Phenda-Ruexhibited a higher rate of CO formation and selectivity compared to bare Tpa-Phenda. This can be attributed to the presence of the coordinated RuIIcenter in Tpa-Phenda-Ru, which acts as a catalytic site. Interestingly, Tpa-Phendashowed a low exciton binding energy (78 meV), which enhances the charge transfer efficiency and minimizes the energy loss. From an in situdiffuse reflectance FTIR spectroscopy (DRIFTS) study together with DFT calculation, a possible catalytic cycle for CO formation was constructed. |
