Fast Photocatalytic U(VI) Reduction Through an Organic Hybrid Silver Antimony Sulfide Featuring a Two‐Dimensional Anionic Layer With Strong Affinity to U(VI)

ABSTRACT Due to open framework structures and the affinity of negatively charged metal sulfide frameworks to UO ₂ ²⁺ cations, organic hybrid metal sulfides could serve as promising photocatalysts for U(VI) reduction. However, application of such materials in photocatalytic U(VI) reduction has never been tried to date. Herein, an organic hybrid silver antimony sulfide [1,4‐DABH ₂ ][Ag ₃ Sb ₃ S ₇ ] (1,4‐DAB = 1,4‐diaminobutane), named DSAS, has been synthesized and used for photocatalytic U(VI) reduction. DSAS features a 2D negatively charged [Ag ₃ Sb ₃ S ₇ ] _n ²ⁿ⁻ anionic layer, which can attract UO ₂ ²⁺ cations through electrostatic interaction, thereby improving the adsorption of UO ₂ ²⁺ cations. To accelerate the separation of electron‐hole pairs in DSAS, a series of DSAS@In ₂ S ₃ ‐ x ( x = 15, 30, 45) composites was prepared by grinding DSAS with In ₂ S ₃ . Energy band structures and in situ irradiated XPS proved the type‐II heterojunction formed between DSAS and In ₂ S ₃ , which accumulated photoelectrons on the DSAS for U(VI) reduction. Consequently, the DSAS@In ₂ S ₃ ‐ x composites exhibited outstanding photocatalytic U(VI) reduction activities. In particular, the U(VI) conversion rate of DSAS@In ₂ S ₃ ‐30 can reach 312 mg g ⁻¹ h ⁻¹ , which is higher than those of most reported photocatalysts. This research proves the feasibility of organic hybrid metal sulfides as photocatalysts for the remediation of U(VI)‐containing wastewater.