Ultrasonic‐Assisted Structural Regulation of CdS Enables Efficient and Stable Photocatalytic Hydrogen Evolution

Cadmium sulfide (CdS), a representative metal sulfide semiconductor, has drawn broad attention for photocatalytic hydrogen evolution due to its favorable band structure and strong visible‐light response. However, its practical application is limited by structural instability and rapid charge carrier recombination. Herein, we develop an ultrasonic‐assisted in situ growth strategy to realize controllable structural reconstruction of CdS hollow assemblies into partially flattened architectures with localized lamellar textures. Structural characterizations confirm that ultrasonic regulation tunes crystal growth orientation, induces highly active surface sites, and boosts charge separation and transfer efficiency. The optimized reconstructed CdS achieves a hydrogen evolution rate of 210.7 μmol h −1 g −1 , an 85% enhancement relative to its hollow counterpart. This improvement benefits from enlarged specific surface area, shortened carrier migration distance, and enhanced structural robustness. Furthermore, ultrasonic‐induced structural reinforcement effectively suppresses photocorrosion, ensuring excellent long‐term stability under light irradiation. This work clarifies the intrinsic correlation between morphology engineering and charge dynamics, offering a facile, generalizable strategy for fabricating high‐efficiency, durable CdS‐based photocatalysts for sustainable hydrogen production.