Construction of Benzodithiophene-Based Donor-Acceptor-Type Covalent Triazine Frameworks with Tunable Structure for Photocatalytic Hydrogen Evolution

The introduction of donor-acceptor (D-A) motifs into organic semiconductors has been considered as one of the effective strategies to regulate photocatalytic activity. Herein, D-A-type benzodithiophene-based covalent triazine framework materials (BDT-CTFs) have been reported. It has been shown that the valence band and conduction band positions, band gaps, and electron-hole separation efficiency can be adjusted by altering the D/A ratio in the BDT-CTF photocatalytic materials. It has been revealed that the high electron-hole separation, migration efficiency, and low electron-hole recombination rates, as well as the special D-A pore structures are the main reasons for the higher photocatalytic hydrogen evolution reaction (HER) activities of BDT-CTF-1 materials. This work revealed the structure-activity relationship in BDT-based CTFs with different D-A ratios, providing a strategy to develop organic photocatalysts with high performance.