Phosphatidyl-assisted fabrication of graphene oxide nanosheets with multiple active sites for uranium(vi) capture

摘要

A novel kind of graphene oxide-based (GO-based) adsorbent was successfully prepared by chemical modification with cetyltrimethylammonium bromide (C(16)TAB) and phytic acid (PA) for adsorbing uranium (U(vi)). A close relationship between PA and GO interlayer spacing was investigated; the optimal spacing was 3.88 angstrom with 4.5 mL PA. A series of adsorption experiments were carried out with the as-prepared product (denoted as GO-C(16)TAB-PA) to capture U(vi) ions. The adsorption capacity of the GO-C(16)TAB-PA adsorbent can reach 923 mg g(-1) (298.15 K) with an excellent removal rate (approximate to 90%), which demonstrates a 527% increment compared with that of pristine GO in the same environment (pH = 8, C-o = 500 mg L-1). Meanwhile, the adsorption equilibrium time of GO-C(16)TAB-PA was shortened by 50% compared with that of pristine GO. In addition, the GO-C(16)TAB-PA adsorbent exhibited superior recyclability with a six-adsorption-desorption-cycle test. Finally, the fabricated GO-C(16)TAB-PA adsorbent exhibited excellent adsorption performance in simulated seawater, providing a theoretical guide and methodology for further seawater extraction of uranium(vi).