| In this paper,based on graphene oxide as raw material,three types of graphene oxide derivative materials have been synthesized.These three kinds of derivative materials have great significance for research due to its characteristics of high adsorption capacity,easy separation,cycle use and green environmental protection.Scanning electron microscope(SEM),transmission electron microscopy(TEM),X-ray diffraction(XRD),infrared spectrometer(FTIR),specific surface area(BET),and X-ray photoelectron spectrometer(XPS)are used to analyze the microstructure of these three kinds of graphene derived materials.Meanwhile,several parameters have been settled to explore the influence for adsorption,such as the solution pH,initial concentration,reaction temperature and reaction time etc.(1)The preparation and characterization of reduced graphene oxide(RGO)and its adsorption for phenol:Hummer method is used to prepare GO and the sodium borohydride is then used to reduce it.One-step reduction method is used to prepare reduced graphene oxide simply.The commonly used characterization methods,XRD,FTIR and so on,are chosen to analyze the RGO.After that,RGO is used to adsorbed the phenol is aqueous solution,in order to purify water.The results show that the adsorption process can be fitted by pseudo-second-order accurately.Langmuir isotherm model is suitable for the adsorption isotherm.At the temperature of 298 K,theoretical adsorption capacity of RGO is 78.26 mg·g-1.Meanwile,through the parameters(△G,△S,△H)from the isotherm,the adsorption of phenol on RGO is a spontaneous process.(2)The preparation of magnetic amino graphene oxide composites(AMGO)and its adsorption of Cr(Ⅵ):the AMGO is synthesized by classical hydrothermal method which just use one step.AMGO is a kind of magnetic adsorbent which can be used to remove Cr(Ⅵ)in aqueous solution.It has good magnetic separation characteristics.The magnetic separation process only needs 40s.From the research,the maximum adsorption capacity is 123.4 mg·g-1,which indicates high efficiency in the process.The adsorption process is affected by pH and it is a spontaneous endothermic process.The pseudo-second-order model and Langmuir model is fitter than other models for adsorption experimental data.In addition,the adsorption mechanism shows that the adsorption process reacts by sequestration and ion exchange.(3)Interaction between U(Ⅵ)with sulfhydryl groups functionalized graphene oxides investigated by batch and spectroscopic techniques:A novel 4-aminothiophenol functionalized graphene oxide composite(GO-SH)was prepared by an easy reaction route.GO-SH is used as adsorbent to remove U(Ⅵ)in aqueous solution.The results show that when T=298 K and pH=5.5,GO-SH has the maximum adsorption capacity of 281.69 mg·g-1.The correlation coefficient of pseudo-second-order is higher.In addition,XRD,FTIR,XPS and mapping is used to study the adsorption mechanism of U(Ⅵ).It shows that the-SH on the surface take part in the adsorption process which complex with the functional groups in order to remove the U(Ⅵ)in aqueous solution. |
