Green Hybrid Reduced Graphene Oxide/iron Nanoparticles And Their Adsorption Of Pb(?)

To obtain low-cost and eco-friendly adsorbent used to remove metals ions,developing biosynthesis nanomaterials is one of the effective methods.In this study,reduced graphene oxide(rGO)with a high compatibility prepared by Eucalyptus leaves extract has been developed.The surface of rGO was capped by numerous oxygen-containing functional groups resulted in biosynthesis,and used to remove metal ions in aqueous solution,where adsorption conditions were optimized.In addition,the thermodynamic and kinetic models revealed that the removing metal ions by rGO was spontaneous and endothermic attributed to the complex adsorption reaction.To addressed the limitions of agglomeration,poor dispersibility in aqueous solution,and high cost of rGO prepared,the hybrided rGO and iron nanoparticles(Fe NPs)was prepared by one-step using Eucalyptus leaf extract at 80 C.The obtained rGO/Fe NPs was characterized by TEM,XPS,XRD and FTIR.rGO/Fe NPs was constituted by graphene nanosheets irregularly embeded with Fe3O4 nanoparticles at a size of 20-40 nm,and its surface was covered with large amount of active organic substances from Eucalyptus leaf extract.In addition,GC-MS was used to indenfy the changes of main active substances in the Eucalyptus extract before and after the synthsis of rGO/Fe NPs.The result showed that 13 organic molecuses in the extract of Eucalyptus leaves participated in the sysnthsis of rGO/Fe NPs,and 1,2,3-Benzenetriol may been the main reducing agent.rGO/Fe NPs showed a certain particle size,good dispersibility in aqueous solution,high specific surface area and considerable active sites for adsorption of Pb(?),and therefore a higher adsorption rate for Pb(?)than that of rGO and Fe NPs.The adsorption of Pb(?)by rGO/Fe NPs was a spontaneous endothermic,which dominated by monolayer adsorption and the theoretical maximum saturated sorption capacity of Pb(?)was reached 101.01 mg/g,which accomplished mainly via complex adsorption.