Synthesis of amino acid modified MIL-101 and efficient uranium adsorption from water

Three novel uranium adsorbents were synthesized by modifying MIL-101 with three amino acids: glycine, histidine and cysteine. The BET (Brunauer-Emmett-Teller) specific surface areas of amino acid modified MIL-101 (MIL-101-Gly, MIL-101-His and MIL-101-Cys) are 429 m(2).g(-1), 713 m(2).g(-1) and 104 m(2).g(-1), respectively, indicating that the modified MIL-101 retained high specific surface area. All the modified MIL-101 s showed good uranium adsorption performance, in which the uranium adsorption performance of MIL-101-His is the best that can reach 345 mg.g(-1) at pH = 6. The adsorption process of three amino acid modified MIL-101 s all accord with Langmuir and pseudo-second-order model for monolayer chemical adsorption. In the existence of K, Ca, Na, Sr, Ba, Cd, Co and Pb, the uranium (VI) removal rate of MIL-101-His can reach 74% indicating its excellent selectivity. After five adsorption-desorption cycles, the adsorption capacity of MIL-101-His still remains good capacity of 300 mg.g(-1). In short, we prepared three novel amino acid modified MIL-101 s, and the histidine modified MIL-101 showed the best uranium adsorption performance, including adsorption capacity, selectivity and recyclability. (C) 2021 Elsevier B.V. All rights reserved.

Automated summary

Three novel uranium adsorbents were synthesized by modifying MIL-101 with three amino acids: glycine, histidine, and cysteine. Among them, the histidine modified MIL-101 showed the best uranium adsorption performance, including capacity, selectivity, and recyclability. The uranium (VI) removal rate of the histidine modified MIL-101 reached 74% in the presence of various ions, indicating excellent selectivity.