Facile Introduction of Quantum Confinement in Linear Conjugated Polymers for Photocatalytic Hydrogen Evolution.

While the structurally tunable nature of Linear conjugated polymers (Linear CPs) offers promising opportunities for advancing photocatalysts, their current fabrication methods predominantly yield particles or bulk materials, significantly hindering the full exploitation of their catalytic potential. In this study, we demonstrate that the inherent entangled state of Linear CPs can be retained before bulk formation, leading to enhanced catalytic performance. Without exfoliation or modified synthesis, the entangled Linear CPs displayed a quantum confinement effect, leading to blue-shifted absorption and emission along with improved carrier separation efficiency. The entangled P28-E exhibits a photocatalytic hydrogen evolution rates (HERs) of 42.8 mmol h g, which is 28 times higher than that of its bulk counterpart (P28-S). A notable trend was observed in the HERs. A notable order shift occurred from P28-S < TpPz-COF, PBT-S, P7-S in the bulk to P28-E > TpPz-COF, PBT-E, P7-E in the entangled state. This work not only presents an effective approach toward efficient photocatalytic water splitting, but also provides new insights into exploring potential microscopic features of Linear CPs.