Steering interfacial charge transfer via 2D-1D MoPS₃-CdS heterojunctions for highly efficient visible-light-driven uranium(VI) remediation

Addressing the urgent demand for the remediation of uranium-contaminated wastewater, the development of highly efficient and stable photocatalysts capable of reducing soluble U(VI) to insoluble U(IV) is of critical significance. Herein, a stable 2D-1D MoPS₃-CdS heterostructure was fabricated via an interfacial assembly strategy. The optimized 3% MoPS₃-CdS heterojunction achieved 99.3% U(VI) removal within 15 min, exhibiting exceptional reaction kinetics, robust tolerance to coexisting ions, and excellent cycling stability. Radical-trapping experiments and electron spin resonance (ESR) measurements revealed that photogenerated electrons and superoxide radicals (•O₂^-) serve as the primary active species driving U(VI) reduction. The enhanced photocatalytic performance is attributed to efficient interfacial charge transfer and spatial charge separation. This mechanism was further supported by fs-TAS measurements and DFT calculations, which revealed pronounced interfacial charge redistribution and provided insights into the charge-transfer characteristics of the Schottky-type heterojunction. This work provides a robust design principle for engineering Schottky-type heterojunctions toward high-performance photocatalytic uranium remediation.