Urazole-decorated multifunctional mesoporous polymer networks for efficient capture of uranium(vi) from aqueous matrices

Abstract

Efficient uranium capture from various water matrices is of paramount importance for sustainable nuclear energy development, as it can mitigate uranium resource limitations and reduce environmental pollution. Herein, we report a multifunctional mesoporous polymer network containing urazole groups, in combination with other groups, such as amines and imines, to achieve excellent uranium uptake efficiency. The developed material exhibits an excellent uranium adsorption capacity of 956 mg g⁻¹ (pH 6), with fast adsorption kinetics (able to capture >75% uranyl from aqueous solutions in just 15 minutes and reaches equilibrium within just 50 minutes). The material can capture >90% uranium from contaminated natural water and wastewater matrices. Moreover, it can extract >70% uranium from natural seawater within 3 days. DFT calculations reveal that the newly introduced urazole groups in the backbone enable excellent binding with uranyl, as understood by its highly negative adsorption energy (ΔE). Its exceptional thermochemical stability, reusability, and uranium-capture efficiency are demonstrated across real-life conditions, such as at varying pH, in the presence of competing ions, and in a range of complex natural and wastewater matrices, including uranium extraction from seawater, and it exhibits superior performance in dynamic column-based systems. These advantages make it a highly promising candidate for practical deployment.