Light-driven boosted uranium adsorption on phosphate-modified MXene hydrogel for remediation of uranium-bearing wastewater

Nuclear energy expansion drives increasing uranium demand, yet acidic in-situ leaching generates toxic, radioactive wastewater that poses severe ecological and health risks. Conventional treatment methods face efficiency, cost, and operational constraints, necessitating high-performance adsorbents. Here, we report a phosphate-functionalized MXene composite hydrogel (P(AM-VPA)/MXene) synthesized via in-situ polymerization for uranium capture. The material demonstrates exceptional mechanical stability, efficient photothermal conversion, a Langmuir-estimated maximum monolayer adsorption capacity of 1376.75 mg·g −1 at pH 6, high selectivity for uranium over competing metal ions, and 89.8% capacity retention after six adsorption-desorption cycles. Under visible light irradiation, adsorption efficiency increases by 18.4% due to accelerated ion diffusion. MXene reinforcement optimizes the hydrogel’s porous architecture while providing abundant active sites, synergizing with phosphate groups to enable chemisorption-dominated uranium binding. This work provides a phosphate-functionalized MXene-hydrogel design that integrates U(VI)-binding phosphate groups, MXene-induced structural reinforcement, recyclability, and photothermal-assisted adsorption, offering a complementary strategy for uranium-bearing wastewater treatment.