Core-shell MoO3-X@ZnIn2S4 with homometallic ion-doped and heterogeneous interface for boosting photocatalytic removal U(VI) in seawater

Photocatalytic technology plays a critical role in uranium extraction by converting soluble U(VI) into insoluble U(IV), underscoring the need to develop efficient catalysts for the photoreduction of U(VI) in aqueous environments. To address this challenge, researchers have developed core–shell MoO 3-X @ZnIn 2 S 4 (M@ZISn) photocatalysts, co-regulated through homometallic ion doping and heterojunction engineering, for U(VI) extraction. The M@ZIS 0.5 photocatalyst demonstrated outstanding performance, achieving a removal rate of 98.84 % and a removal capacity of 296.52 mg·g −1 within 90 min. Optical characterization revealed that its superior photocatalytic activity stems from three key factors: (1) Mo 5+ doping and heterojunction formation effectively suppressed the recombination of photogenerated electron-hole pairs, (2) the core–shell structure provided an efficient pathway for the transfer of photogenerated carriers, and (3) Density Functional Theory (DFT) calculations confirmed that homometallic ion doping and heterojunction engineering optimized the semiconductor’s bandgap structure and enhanced its performance. Notably, when applied to spiked natural water samples (from the Yellow River, Salt Lake, and seawater), the M@ZIS 0.5 catalyst maintained a high removal rate of 78.82 %, demonstrating its potential for practical applications in real-world water systems.