Constructing\nthe Electron-Rich Microenvironment of\nan All-Polymer-Based S‑Scheme Homostructure for Accelerating\nUranium Capture from Nuclear Wastewater

Large\nquantities of uranium-containing radioactive wastewater are\ntypically generated during nuclear fuel cycle processes. Despite significant\nefforts, efficient capture of migratable hexavalent uranium U(VI)\nis still a huge challenge due to its acidity, radioactivity, coexisting\norganics, and high impurity cation abundance in wastewater. Herein,\nwe have fabricated all-polymer-based 0D/2D C<sub>4</sub>N/C<sub>6</sub>N<sub>7</sub> homostructure hybrids with an S-scheme electronic configuration\nby coordinating the band engineering of semiconductors to enrich uranium\nspecies from the complex wastewater environment. The sample can capture\nover 97% of U(VI) in the actual concentration of nuclear industrial\nreprocessing wastewater; also, the U(VI) enrichment ratio still exceeds\n95% when the irradiation dose (including α, β, and γ)\nis up to 100 kGy. Density functional theory and X-ray absorption spectroscopy\ndemonstrate that the aggregation of charge carriers on the surface\nof the sample regulates the electron-rich microenvironment, thus accelerating\nthe reduction conversion of single electron reaction uranium disproportionation.\nIt is expected that this work can provide more insight into other\nfunctional materials, thereby promoting uranium removal advancements\nin nuclear wastewater.