Cd Doping as a Dual-Functional Promoter: Steering Interfacial Architecture and Creating Active Sites for Exceptional Photocatalytic Uranium Extraction

Abstract The photocatalytic reduction of soluble U(VI) to insoluble U(IV) is a promising strategy for uranium extraction and wastewater remediation. Herein, we rationally design a Cd-doped ZnO/BiOCl direct Z-scheme heterojunction, where Cd serves a dual-functional role grounded in its optimal ionic radius match with Zn2+ and unique electronic configuration. Cd acts as a morphology-directing promoter to regulate BiOCl nucleation, building an intimately interlocked heterointerface for efficient charge transfer, while simultaneously introducing oxygen vacancies that synergize with BiOCl-derived Cl– sites to form dual-functional active centers for UO22+ adsorption and activation. This synergistic architecture achieves 94.14% U(VI) removal within 180 min under simulated sunlight with excellent stability and selectivity. This work presents a unified strategy for engineering both interfacial architecture and surface reactivity for advanced photocatalysis.