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.

Automated summary

Surface and interface engineering is utilized to convert soluble hexavalent uranium (U(VI)) into insoluble tetravalent uranium (U(IV)) through the fabrication of surface oxidized tin disulfide nanosheets (O-SnS2) on tellurium nanowires (Te@O-SnS2). The Te@O-SnS2 photocatalysts demonstrate high efficiency in U(VI) removal, with a notable capacity for handling interfering ions and maintaining removal efficiency under varying pH conditions.