Selective capture of radionuclides (U, Pu, Th, Am and Co) using functional nanoporous sorbents

•3,4-HOPO-SAMMS was best at capturing uranium from seawater from pH 2–8.•Ac-Phos-SAMMS was best at capturing uranium at below pH 2.•3,4-HOPO-SAMMS was effective at capturing Th and Pu from pH 2–8, and americium from pH 5–8.•IDAA-SAMMS was most effective at capturing Co from river water from pH 5–8.•Over 99% of U and Co was captured by 3,4-HOPO- and IDAA-SAMMS from seawater within 5 min. This work evaluated sorbent materials created from nanoporous silica self-assembled with monolayer (SAMMS) of hydroxypyridinone derivatives (1,2-HOPO, 3,2-HOPO, 3,4-HOPO), acetamide phosphonate (Ac-Phos), glycine derivatives (IDAA, DE4A, ED3A), and thiol (SH) for capturing of actinides and transition metal cobalt. In filtered seawater doped with competing metals (Cr, Mn, Fe, Co, Cu, Zn, Se, Mo) at levels encountered in environmental or physiological samples, 3,4-HOPO-SAMMS was best at capturing uranium (U(VI)) from pH 2–8, Ac-Phos and 1,2-HOPO-SAMMS sorbents were best at pH DE4A > ED3A > Ac-Phos > SH on SAMMS. Iminodiacetic acid (IDAA)-SAMMS was also outstanding at capturing Co(II) in ground and seawater. Within 5 min, over 99% of U(VI) and Co(II) in seawater was captured by 3,4-HOPO-SAMMS and IDAA-SAMMS, respectively. These nanoporous materials outperformed the commercially available cation sorbents in binding affinity and adsorption rate. They have great potential for water treatment and recovery of actinides and cobalt from complex matrices.