Tellurium nanowires wrapped by surface oxidized tin disulfide nanosheets achieves efficient photocatalytic reduction of U(VI)

Surface and interface engineering represents a powerful strategy for photocatalytic reduction of soluble hexavalent uranium (U(VI)) into insoluble tetravalent uranium (U(IV)). Herein, we fabricated surface oxidized tin disulfide nanosheets (O-SnS2) on tellurium nanowires (Te@O-SnS2) as highly efficient and stable photocatalysts for U(VI) removal from wastewater. In this system, the Te nanowires increased the surface negative charge and resulted in the injection of hot electrons into O-SnS2 nanosheets, which facilitated the binding and reduction of U (VI) on the abundant surface defects of O-SnS2. Under the irradiation of simulated sunlight, the removal efficiency toward U(VI) by Te@O-SnS2 reached 97.3% in 60 min with the initial U(VI) concentration of 8 mg/L. Additionally, the maximum extraction capacity of U(VI) by Te@O-SnS2 reached 704.8 mg/g at the initial U(VI) concentration of 200 mg/L. Furthermore, the Te@O-SnS2 exhibited remarkable resistence ability for the interfering ions and a U(VI) removal efficiency > 88.4% over a wide range of pH, and maintained a high U(VI) removal efficiency (>92%) during cycle tests at pH 4.8.