Green Synthesis,Characterization Of Graphene And Its Adsorption Properties

Graphene is a popular material since it has a wide range of potential applications.In the recent years,there are many methods used for the graphene synthesis.However,while its structure and property depends on the preparation methods.In this work,we developed a green and facile method by reduced graphene oxide(GO)using eucalyptus leaf extract,which is main plant with rapid growth in Fujian province.The conditions for reduced graphene oxid(temperature,time and concentration of EL)were optimized,and following the structure and property of EL-RGO were characterized.The results show that the thickness of EL-RGO sheet was about 1.129 um,indicating that it not only has a good dispersibility and environmental friendly,but also a good thermal stability and electrochemical properties.Besides,green synthesis advoids the disadvantage of toxicity,aggregation and higher cost,and also improve the biocompatibility of graphene.It prompted that the application potential in fields of microbial fuel cells,biological medicine and elecrtochemical biosensor.Since there are a large number of minor ?electron bond in the EL-RGO layer,and it was used to remove metal ions and aromatic organic compounds.The structure and property of GO synthesized through the modified hummers.method was characterized.It was found that GO had the potential as an efficient adsorbent to remove the contaminants from water,owing to its high specific surface area and oxygen-containing functional groups,resulting in abundant adsorption sites exiting on GO.Therefore,GO was used to adsorb Cu(?),Methylene blue(MB)and MB-Cu(II)coexist pollutants from water.In single pollutant system,the maximum adsorption capacities of Cu(II)and MB were 424.16 mg/g and 29.13 mg/g,respectively.While both the adsorption capacities of Cu(II)and MB decreased in Cu(II)-MB binary system,indicating that the competitive adsorption of MB and Cu(II)greatly influences their adsorption behavior on GO.These results revealed that MB has a far greater impact on GO adsorption performance than Cu(II).The adsorption mechanism of GO for MB is main attributed to its surface of ? bonds form n-n stacking of chemical adsorption,and the surface of oxygen-containing groups adsorption MB by electrostatic interaction.However,the surface of EL-RGO? electtron conjugated system has a better recovery by the process reduction of GO,and it may form a stronger ?-?stacking for adsoption MB.The adsorption property of EL-RGO on MB was also studied to explore whether it will show greater adsorption potential.Firstly,comparing the adsorption properties of EL-RGO on 50 mg/L MB with commercial graphene,activated carbon and graphite powde,the results showed that the adsorption property of EL-RGO was best,the maximum adsorption capacity was 49.92 mg/g,followed by commercial graphene(25.05 mg/g),activated carbon(10.62 mg/g)and graphite powder(7.39 mg/g).Subsequently,the adsorption mechanism of MB on EL-RGO was investigated.It was found that the adsorption mechanism of EL-RGO on MB is the same as that of GO,which is dominated by chemical adsorption and physical adsorption,single phase adsorption and multi phase adsorption.The adsorptive of MB on EL-RGO by the conjugated system was less than GO,and it was proved that the oxygen-containing functional groups in GO had a great effect on the adsorption of MB.