Reducing the Exciton Binding Energy of Donor-Acceptor-Based Conjugated Polymers to Promote Charge-Induced Reactions

Angew Chem Int Ed Engl. 2019 Jul 22;58(30):10236-10240. doi: 10.1002/anie.201904904. Epub 2019 Jun 24.

Abstract

Exciton binding energy has been regarded as a crucial parameter for mediating charge separation in polymeric photocatalysts. Minimizing the exciton binding energy of the polymers can increase the yield of charge-carrier generation and thus improve the photocatalytic activities, but the realization of this approach remains a great challenge. Herein, a series of linear donor-acceptor conjugated polymers has been developed to minimize the exciton binding energy by modulating the charge-transfer pathway. The results reveal that the reduced energy loss of the charge-transfer state can facilitate the electron transfer from donor to acceptor, and thus, more electrons are ready for subsequent reduction reactions. The optimized polymer, FSO-FS, exhibits a remarkable photochemical performance under visible light irradiation.

Keywords: charge-transfer pathway; conjugated polymer; exciton binding energy; hydrogen evolution; photocatalysis.