Triptycene incorporated carbon nitride based donor-acceptor conjugated polymers with superior visible-light photocatalytic activities

Polymeric carbon nitride (CN) has evoked considerable attention in photocatalysis, however, its p- deficiency conjugated frameworks engendering weak visible-light absorption and rapid charge recombi-nation hinder the practical utilizations. Herein, a novel donor acceptor (D-A) conjugated polymer based on triptycene incorporated carbon nitride (T-CN) has been facilely prepared by thermal copolymerization of melamine and 2,6,14-triaminotriptycene. Combined with the density functional theory (DFT) calcula-tions, it is found that the formation of intramolecular charge transfer and the extended p-conjugative effect in the D-A structure contribute to a broadened light-harvesting spectral range, a higher charge sep-aration/transfer efficiency and more active sites of T-CN for photoredox reactions. The T-CN catalyst accomplished superior visible-light photocatalytic performance in both hydrogen evolving and carbon dioxide reduction. The optimal T-CN catalyst exhibited the highest hydrogen evolution rate of 80.9 +/- 1. 3 mu mol center dot h(-1) and carbon monoxide production rate of 8.1 +/- 0.2 mu mol center dot h(-1), which are ca. 8-fold and 20 fold of bulk CN, respectively. The convenient strategy of constructing D-A conjugated structure opens up a new intriguing avenue toward the rational creation of efficient polymeric nanomaterials for versatile applications of solar fuel production. (c) 2022 Elsevier Inc. All rights reserved.