Design and synthesis of semiconducting polymers for solar-driven hydrogen evolution from water

This work focuses on developing visible-light-driven hydrogen production from water using polymer photocatalysts, inspired by natural photosynthesis. Since the successful application of graphitic carbon nitride in 2009, various polymeric materials—such as linear conjugated polymers, conjugated microporous polymers, polymer dots, covalent triazine frameworks, and covalent organic frameworks—have been explored for photocatalytic hydrogen evolution. Organic semiconductors are attractive due to their tunable structures and low-temperature processability. However, their inherent hydrophobicity limits performance in aqueous environments. Traditional strategies to enhance hydrophilicity include side-chain engineering or amphiphilic modifications. Our group proposes a new approach by integrating hydrophilic building blocks into the polymer backbone, producing discontinuously conjugated structures that improve water compatibility without compromising semiconductor properties. Moreover, while most studies use pure water, this is not practical for large-scale application. Seawater contains ions that compete for active sites, reducing catalyst activity and stability. This presentation introduces a series of newly designed polymer photocatalysts for solar-driven hydrogen generation, with a particular focus on addressing interfacial challenges between the polymer, seawater, and co-catalysts. These insights provide a clear strategy for improving hydrogen evolution efficiency and durability under more realistic and sustainable conditions.