Electron localization of ZnO/Znln2S4 interface induced lattice relaxation for triggering photocatalytic uranium evolution

Designing a material that efficiently extracts uranium (U) from natural seawater and resists biofouling remains a critical challenge. Here, flake Znln2S4 grew in situ on the surface of black porous zinc oxide (B-ZnO), and finally a binary composite material (B-ZnO/ZnIn2S4) is synthesized. Based on the reduction process of U(VI), the chemical reaction of the U(VI) → U(IV) process occurred on the surface and interface of the composite material. The S-scheme heterojunction system constructed of ZnO and Znln2S4 with a matching band structure showed great potential for promoting the separation and transfer of photogenerated carriers and obtaining powerful photoredox capabilities. By generating biologically toxic free radical reactive oxygen species and Zn2+, the adsorbent had high antibiological fouling activity. After 120 min of extraction in simulated seawater, the light-induced reduction ability of B-ZnO/ZnIn2S4-45% (mass ratio) on U(VI) reached 99%, which was 6.2 times higher than that under dark conditions. The conversion path of U(VI) was calculated by density functional theory (DFT). In addition, ZnIn2S4 (0 0 7) exhibited the ability to localize to the surface of ZnO (0 0 2) and promote electron transfer. These results indicate that interface atomic structure engineering is crucial for the synthesis of efficient and durable seawater U(VI) extraction catalysts.