Effect of Linking Pattern of Dibenzothiophene-S,S-dioxide-Containing Conjugated Microporous Polymers on the Photocatalytic Performance

Conjugated microporous polymers (CMPs) exhibit great potential for photocatalytic hydrogen generation due to their tunable electronic structure. The rational molecular design is a key point for developing an efficient CMP photocatalyst. Herein, we developed two CMPs photocatalysts via the copolymerization from pyrene and dibenzothiophene-S,S-dioxide building blocks. The effect of the linking pattern of the building block of dibenzothiophene-S,S-dioxide on the photocatalytic hydrogen evolution was explored. The polymer of PyDOBT-1 with 3,7-linking pattern shows a superior photocatalytic performance to PyDOBT-2 with 2,8-linking pattern because the 3,7-linking pattern enhances the conjugation chain length and improves the coplanarity of the polymeric backbone, which facilitate the charges migration along the polymer chain. As a result, the bare PyDOBT-1 shows an impressive visible light activity with a hydrogen evolution rate (HER) of 5697 μmol h–1 g–1. Notably, an outstanding HER of 12986 μmol h–1 g–1 was also obtained by the Pt-modified PyDOBT-1 under the full-arc spectrum (λ > 300 nm), which lies toward the upper end compared to that of the reported organic photocatalysts.