Facile synthesis of hierarchical Fe4(P2O7)3 for removal of U(VI)

Abstract

Fe4(P2O7)3 was successfully synthesized by using high temperature solid state reaction method and characterized by scanning electron microscopy (SEM), powder X-ray diffraction (XRD) and Fourier transformed infrared spectroscopy (FT-IR). The as-synthesized Fe4(P2O7)3 was applied as adsorbent to adsorb U(VI) ions from aqueous solutions and the material exhibited high sorption capacity for U(VI). The effect of contact time, pH, ionic strength, solid content and temperature on U(VI) sorption to Fe4(P2O7)3 was investigated by using batch technique. The results demonstrated that the sorption of U(VI) was independent of ionic strength, indicating that the sorption was mainly dominated by inner-sphere surface complexation. The thermo-dynamic parameters (ΔG0, ΔS0 and ΔH0) were calculated from the temperature-dependent sorption isotherms, and the results suggested that the sorption of U(VI) was a spontaneous and endothermic process. To get a better understanding of the interaction mechanism between U(VI) and Fe4(P2O7)3, the U(VI) adsorbed Fe4(P2O7)3 was characterized by SEM, XRD and FT-IR. The results might be important for the application of Fe4(P2O7)3 in the field of U(VI) pollution management.