Amidoxime-Based Polymer Microspheres with High Selectivity for Uranium from Saline Lake Brine

Uranium is the most basic ingredient for nuclear energy production, and its sources are mainly concentrated in mineral, as well as seawater and saline lake brine. Amidoxime-based functional adsorbents play an indispensable role in the efficient recovery of uranium from varied sources. However, it is empirically considered that for amidoxime adsorbents, balancing adsorption capacity and selectivity is challenging in the presence of complex interfering ions, especially for vanadium. Herein, a kind of amidoxime-modified mesoporous polymer microsphere with an optimized distance among functional groups was synthesized, which has remarkable chemical stability and ion selectivity. It is impressive that the adsorption capacity of the above-mentioned amidoxime microspheres for uranium in natural saline lake brine reached 15.9 mg/g, which was two orders of magnitude higher than that of vanadium. Combined with enhanced adsorption capacity, excellent selectivity, and ultra-high stability, amidoxime-functionalized mesoporous polymer microspheres emerge as a promising adsorbent for uranium extraction from natural saline lake brine.