Fabric‐Based Dot‐in‐Caged AgInS2@CdS Heterojunction for Highly Efficient Photocatalytic Uranium Extraction via Reductive Crystallization

Abstract Photocatalytic uranium extraction has emerged as a promising strategy for recovering uranium from nuclear wastewater and seawater. Designing photocatalysts with high reduction efficiency and effective uranium enrichment is crucial for advancing this approach. Herein, a novel uranium extraction strategy is proposed, integrating photocatalytic reduction with assembly‐assisted crystallization, utilizing a Cd‐ZIF‐8‐derived dot‐in‐caged AIS@CdS fabric, which can operate under weak sunlight, eliminate the need for sacrificial agents, and overcome recovering powdered catalysts in marine environments. The optimized 4AIS@CdS achieved a remarkable uranium removal efficiency of 99.3% under visible light without sacrificial agents, with a reaction rate of 2.1 times and 37.3 times higher than CdS and AIS, respectively. Structural investigations revealed the formation of needle‐like crystals of UO 2 in AIS@CdS fabric. Band analysis suggests that the heterojunction between AIS and CdS facilitates the separation/transfer of photogenerated carriers, while the dot‐in‐caged structure provides suitable thermodynamic circumvents for reductive crystallization of U(VI). The 4AIS@CdS fabric achieved a uranium extraction capacity of 1.05 mg g −1 after 15 h of sunlight irradiation. These findings not only offer a new pathway for efficient uranium recovery from aqueous solutions under weak light conditions but also highlight the potential of fabric‐based photocatalytic systems for scalable and sustainable uranium extraction.