Boosting efficient U(VI) immobilization via synergistic Schottky heterojunction and hierarchical atomic-level injected engineering

Nuclear power has brought promising energy sources while laying down the potential risks for environmental friendliness. The technology that converting mobile U(VI) to immobilized U(IV) via photocatalytic reduction is considered to be an effective strategy for treatment spent fuel wastewater systems. Here we employed S-injected engineering to functionalize atoms in the TiO2/N-doped hollow carbon sphere (TiOS/NHCS) heterostructure to obtain exciting U(VI) removal efficiency. The experimental results suggested that the U(VI) reduction efficiency exceeded 90% in 20 min at a low initial concentration of 10 mg L-1, and even the removal ratio per unit mass reached 448 mg. Density functional theory calculations further proved that the injected S-atoms optimized the energy level structure of TiO2 and strengthened the light utilization ability. Additionally, the remarkable effect benefit forms the spatial separation of photogenerated electrons by the Mott-Schottky junction and the optimization of the TiO2 energy-level structure by functionalized atoms. It is believed that this work will lay a foundation for the atomic functionalization of photocatalysts and the collaborative design of more advanced injection engineering and Schottky junction for enriching uranium-containing wastewater in the future.