The enhanced co-catalyst free photocatalytic hydrogen evolution and stability based on indenofluorene-containing donor-acceptor conjugated polymer dots/g-C3N4 nanosheets heterojunction

Due to the longer conjugation length and higher rigidity of the indofluorene, poly(indenofluorene) (PIF) demonstrates better optical absorption capability and faster carriers mobility than the corresponding polyfluorene (PF). In this study, a donor-acceptor (D-A) type PIF (PIFDTBT) is synthesized and coupled with g-C3N4 nanosheets to construct conjugated polymer dots/g-C3N4 nanosheets (Pdots/CNNS). Ascribed to the enhanced light absorption, suitable band positions, and outstanding carriers mobility resulted by the introduction of indenofluorene units, the HER of PIFDTBT Pdot/CNNS is 7.6 times higher than that of F8DTBT Pdots/CNNS at the 1st run without metallic co-catalyst. Interestingly, the HER enhancement of PIFDTBT Pdots/CNNS compared to F8DTBT Pdots/CNNS correspondingly increases from 7.6 times at the 1st run to 14.3 times at the 4th run. This research can provide an insight for constructing organic nanocomposites with improved optical response and enhanced stability by electron donor units adjustment of the conjugated polymer.