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

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). Environmental significance Exploitation of alternative uranium ( U.VI)) sources to ensure the long-term availability of this nuclear fuel is of great importance to the development of nuclear fuel; particularly, extraction of U.VI) from seawater. However, the design of an acceptable interlayer spacing, suitable seawater pH and a highly adsorbing adsorbent for the capture of U.VI) from seawater is still challenging. In this work, we constructed a suitable adsorbent by chemical modification with cetyltrimethylammonium bromide ( C16TAB) and phytic acid ( PA) for adsorbing U.VI). We show a close relationship between PA and GO interlayer spacing, optimized at 3.88 A with 4.5 mL PA. In the process, the as-prepared product ( denoted as GO-C16TAB-PA) exhibited very fast response and a high reaction rate due to an acceptable interlayer spacing, suitable seawater pH and multiple active sites, which are superior to most results of current adsorbents reported in the literature. The contents are most important for providing a theoretical guide and methodology for further seawater extraction of uranium.