Porous carboxylated carbon nanotubes hydrogel microspheres for removing U(VI) from aqueous solutions

To efficiently remove U(VI) from aqueous solutions, porous polyvinyl alcohol/carboxylated carbon nanotubes/sodium alginate (PPCS) hydrogel microspheres were prepared using the physical cross-linking method. The successful formation of highly porous PPCS hydrogel microspheres was confirmed by SEM and BET. Moreover, PPCS hydrogel microspheres were recovered from aqueous solutions more easily than carbon nanotubes. The main mechanism of PPCS for U(VI) removal may be the chelation of hydroxyl and carboxyl groups. PPCS may be a promising and recyclable adsorbent for uranium extraction. Graphical abstract