Dual-active-site PDA@PW 12 microspheres for high-efficiency uranium extraction via synergistic complexation and reduction

In this study, PDA@PW12 composite microspheres were successfully prepared through in situ co-polymerization of dopamine and phosphotungstic acid for efficient uranium adsorption. Characterization results demonstrated that the incorporation of PW12 not only inhibited the agglomeration of PDA but also increased the specific surface area to 48.07 m2/g, while simultaneously generating W5+ active species through electron transfer. The material achieved a maximum uranium adsorption capacity of 720.1 mg/g at pH = 5 and 318 K, with the adsorption process following the pseudo-second-order kinetic model and Langmuir isotherm model, indicating spontaneous monolayer chemisorption. Mechanistic investigations confirmed that uranium adsorption was realized through the synergistic effect of surface complexation by functional groups (-OH/-NH2) and the reduction of U(VI) to U(IV) by W5+ species. The composite maintained 93.3% desorption efficiency after five adsorption-desorption cycles and exhibited excellent selectivity toward U(VI). This work provides a new strategy for developing high-performance uranium adsorption materials.