Hyperbranched Conjugated Polymer Dots: The Enhanced\nPhotocatalytic Activity for Visible Light-Driven Hydrogen Production

Abstract

Conjugated\npolymer (CP) aggregates with linear/cross-linked structures\nare widely reported as photocatalysts for hydrogen evolution reaction.\nFor full disclosure of the relationship between the photocatalytic\nperformance and structural features of the CP photocatalysts, homogeneous\ndispersion of these CPs in aqueous medium is necessary, which however\nis difficult to be achieved. Herein, we report several coassembled\npolymeric dots (Pdots) consisting of PEG₄₅-<i>b</i>-PMMA₁₀₃ and CPs with various structural features. We\nfound that the Pdots of hyperbranched soluble CP nanoparticles (SCPNs)\nexhibit a high H₂ evolution rate up to 840 μmol h^–1 g^–1 with no platinum or rhodium\nas a cocatalyst, superior to their analogues with the linear or cross-linked\nstructure. A possible charge-transfer mechanism suggests that the\nphotoelectrons directly mobilize to the surface of these single-particulate\nPdots over three-dimensional skeleton and successfully avoid the ineffective\nintermolecular charge transfer, leading to the shortened diffusion\npath of photoelectrons and enhanced photolysis efficacy. We believe\nthat the high dispersion stability (2 months), solution processability,\nand structural tunability of these Pdots with hyperbranched SCPNs\nwould inspire further research on designing multicomponent photocatalysts\nfor highly efficient visible light-driven hydrogen evolution reaction.