Functionalized mesoporous carbon nanospheres for efficient uranium extraction from aqueous solutions

Abstract

The development of effective adsorbents for uranium (VI) extraction from aqueous solutions has received great significance for environmental security. Herein, we reported a versatile and straightforward strategy for the synthesis of amidoxime-functionalized mesoporous carbon nanospheres (MCNs-AO). This method utilized the chemical grafting of amidoxime functional groups to the mesoporous carbon nanospheres. The resultant MCNs-AO was highly active, selective, and recyclable adsorbent for U(VI) extraction from aqueous solutions. MCNs-AO showed the maximum adsorption capacity of 627.2 mg·g1 at 298 K and pH = 5.5, much higher than MCNs (58.2 mg·g1) and other materials. Batch and fixed-bed column experiments indicated that the highly accessible amidoxime groups serving as the active sites are critical to U(VI) adsorption performance on MCNs-AO. This proof-of-concept study opens a new way to synthesize highly effective, low-cost, and durable adsorbents for the efficient extraction of U(VI).