One‐Dimensional CdS/TpPa‐COF S‐Scheme Heterojunctions Enabling Directional Charge Transport for Highly Efficient Photocatalytic Hydrogen Evolution

ABSTRACT Constructing efficient heterojunctions with accelerated charge separation and directional carries migration is crucial for high‐performance photocatalytic hydrogen evolution. Herein, a 1D CdS/TpPa‑COF S‐scheme heterojunction is rationally constructed via an in situ growth strategy under mild conditions, in which TpPa‐COF is uniformly anchored onto CdS nanorods (NRs) to form an intimate interface. Benefiting from the well‐defined 1D architecture and strong interfacial electronic coupling, the CdS/TpPa‐COF heterostructure exhibits significantly enhanced efficient charge separation, and directional charge transport driven by an internal built‐in electric field. The optimized CdS/TpPa‐COF photocatalyst delivers a remarkable photocatalytic hydrogen evolution rate of 165 mmol·g −1 ·h −1 , which is substantially higher than those of pristine CdS and TpPa‐COF. Notably, excellent hydrogen production performance is also achieved under real sunlight irradiation. The results reveal that spontaneous electron transfer induces band bending and establishes an S‐scheme charge‐transfer pathway, preserving strong redox potentials and enhancing the photocatalytic hydrogen evolution performance. This work highlights the promise of dimensionally regulated 1D COF‐based heterojunctions for advanced solar‐to‐fuel conversion systems.