Linear PDI-based conjugated polymers with directional charge transport driving photocatalytic water oxidation

Abstract

The development of organic polymers with effective charge transfer has great appeal and significance for designing photocatalytic systems to achieve energy storage and conversion. However, charge separation behavior is often constrained by the structure of polymer molecules. Herein, we constructed linear conjugated organic polymers with 3,4,9,10-perylenetetracarboxylic dianhydride (PTCDA) as the basic unit and p,p′-diaminobiphenyl (CB) and 3,7-diaminodiphenylene sulfone (CS) as linkers, named PT-CB and PT-CS, respectively. The achieved linear polymers exhibited directional charge transfer ability and photocatalytic water oxidation performance. Notably, PT-CB exhibited a yield of 966.28 μmol g⁻¹ h⁻¹ in the oxygen evolution reaction, indicating the efficient charge separation in the PT-CB. Theoretical calculation results further indicated that charge carriers in PT-CB molecules were transferred along the chain direction and possess higher mobility than between the chain, demonstrating the capability of directional electron transport. Our work provides a new inspiration and mechanistic insights for designing photocatalysts with directed charge transfer, and offers new ideas for the design of high-efficiency photocatalytic water oxidation systems.