A Self-Assembled Supramolecular Material Containing Phosphoric Acid for Ultrafast and Efficient Capture of Uranium from Acidic Solutions

Herein, we report a convenient method for the preparation of a self-assembled supramolecular material containing phosphoric acid (PM) choosing phytic acid and melamine as the two organic building blocks. The PM was chosen as an adsorbent for the first time for the fast adsorption and recovery of U(VI) from acidic aqueous media. The batch adsorption experiments showed that PM-9 possesses a very fast adsorption kinetic with the adsorption process for U(VI) from acidic water reaching equilibrium within 2 min. A considerable adsorption capacity of 1034.9 mg/g and an excellent selectivity 58.6% toward U(VI) in acidic aqueous solution were obtained. The adsorption capacity in dynamic column experiment was determined to be 251.0 mg g–1, with the recovery efficiency as high as 99.4% when using Na2CO3 as a stripping agent. The adsorption mechanism was probed by FT–IR, XRD, SEM, XRF, and XPS, implying the double bond oxygen atom of phosphoric acid and the nitrogen atom of amino group complexes with uranyl ions in the acidic media.