| Abstract: | Graphene oxide and Ni-Al layered double hydroxides(GO@LDH) nanocomposites were synthesized via a one-pot hydrothermal process,and characterized by X-ray diffraction(XRD),Fourier transformed infrared spectroscopy(FTIR),scanning electron microscopy(SEM),transmission electron microscopy(TEM),X-ray photoelectron spectroscopy(XPS) and Raman spectroscopy in detail.The exploration of U(VI) sorption on GO@LDH surface was performed as a function of ionic strength,solution pH,contact time,U(VI) initial concentrations and temperature.Results of Langmuir isotherms showed that the sorption capacity of GO@LDH(160 mg/g) was much higher than those of LDH(69 mg/g) and GO(92 mg/g).The formed surface complexes between surface oxygen-containing functional groups of GO@LDH and U(VI) turned out to be the interaction mechanism of U(VI) with GO@LDH.According to the thermodynamic studies results,the sorption interaction was actually a spontaneous and endothermic chemical process.The sorption isotherms were better fitted with the Langmuir model compared with other models,which suggested the interaction was mainly dominated by mono layer coverage.The GO@LDH nanocomposites provide potential applications as adsorbents in the enrichment of radionuclides from wastewater in nuclear waste management and environmental remediation. |
