Improvement of Photocatalytic CO₂ Reduction with Conjugated Organic Polymers by Rational Modulation of Donor,...

The use of metal-free catalysts to convert CO₂ into valuable chemicals is very challenging. Here, we synthesized a conjugated organic polymer (TpTf-1) featuring 2,4,6-Triphenyl-1,3,5-Triazine as the acceptor unit, triphenylamine as the donor unit, and vinylidene bond as the linkage. The local structure of donor-acceptor (D-A) forms an intramolecular electric field that can promote the separation of photogenerated electrons and charges, meanwhile, the vinylidene bond can further change the charge distribution to promote exciton dissociation. Without the use of photosensitizers, the TpTf-1 exhibits outstanding selectivity of CO of up to 91.96 %, with a production rate of 45.2 μmol g^-1 h^-1 at visible light, which is 3.4-fold than TaTf-1 with the same D-A structure but linking in imine bond and is 2.8-fold than TpTf-2 linking in vinylidene bond but with a different donor unit. Moreover, TpTf-1 has a CO production rate of up to 117.3 μmol g^-1 h^-1 under full wavelength light irradiation.