Hydrophilicity-Controlled Conjugated Microporous Polymers for Enhanced Visible-Light-Driven Photocatalytic H2 Evolution.

To take advantage of high surface area of network conjugated microporous polymers, four linear or network conjugated polymers L-PDBT, L-PDBT-O, N-PDBT, and N-PDBT-O are designed in terms of water-compatibility, and it turned out that microporous network N-PDBT-O exhibited the highest hydrogen evolution rate (HER) at 366 µmol h-1 under visible light irradiation (λ > 420 nm, one of best reported pristine polymer-based photocatalysts), which is three times higher than the corresponding linear L-PDBT-O. Water contact angle measurements revealed that benzothiophene-sulfone-based conjugated polymers display better water compatibility and adsorption, and the synergic effect of better hydrophilic surface and higher surface area of N-PDBT-O might eventually lead to more exposed active sites in comparison to linear L-PDBT-O in the H2 evolution suspension system. The hydrophilicity-controlled strategy could be applied to design of other network conjugated microporous polymer photocatalysts in an attempt to improve the activity.