Photocatalytically active ladder polymers.

ABSTRACT: Conjugated ladder polymers (cLaPs) are introduced as organic semiconductors for photocatalytic hydrogen evolution from water under sacrificial conditions. Starting from a linear conjugated polymer (cLiP1), two ladder polymers are synthesized via post-polymerization annulation and oxidation techniques to generate rigidified, planarized materials bearing dibenzo[b,d]thiophene (cLaP1) and dibenzo[b,d]thiophene sulfone subunits (cLaP2). The high photocatalytic activity of cLaP1 (1307 ?mol h-1 g-1) in comparison to that of cLaP2 (18 ?mol h-1 g-1) under broadband illumination (? > 295 nm) in the presence of a hole-scavenger is attributed to a higher yield of long-lived charges (?s to ms timescale), as evidenced by transient absorption spectroscopy. Additionally, cLaP1 has a larger overpotential for proton reduction and thus an increased driving force for the evolution of hydrogen under sacrificial conditions.

SUBMITTER: Vogel A 

PROVIDER: S-EPMC6677027 | biostudies-literature | 2019 Jul

REPOSITORIES: biostudies-literature