Enhancing photocatalytic hydrogen evolution performance for D-π-A conjugated polymers based on the perylene diimide

Efficient photocatalysts rely on constructing heterostructure with reasonable configuration. In this study, a novel conjugated polymer with a D-pi-A structure was fabricated from polycondensation of perylene diimide and dibenzothiophene sulfone through the suzuki coupling reaction, during which the biphenyl was incorporated as a it-bridge. The photocatalytic hydrogen evolution performance of these copolymers were optimized by introducing different mass fractions of it-bridges via adjusting the additions of biphenyls The optimized PyBpDBSO-5 copolymer, with 17 wt.% perylene diimide and 5 wt% biphenyl, obtained photocatalytic hydrogen productivity of 48.54mmol/h g- 1 under visible light without adding Pt as cocatalyst, which is 146.1 % improvement compared to the poly(dibenzothiophene-S,S-dioxide) (PDBTSO, 19.72mmol/h g- 1). Based on the analysis of physical and chemical properties, electrochemical testing, the significant advantages of D-pi-A configuration in promoting light absorption, photogenerated carriers transfer and separation was confirmed, which was further rationalized by the larger co-planarity of the polymer based on DFT calculations. This study provides inspiration about construction of conjugated organic polymer catalyst towards efficient photocatalysts.