Adsorption Properties Of Sarin Molecular On Fe Modified Graphene

In recent years,chemical agents,which had been widely used in war and terrorist attacks,had caused great harm to human and national security.Therefore,how to eliminate these chemical agents effectively becomes a major challenge for scientific research workers and national security.A safe and effective way to detoxify chemical agents is to choose suitable adsorbents.As a new type of carbon-based materials,graphene has attracted tremendous interest due to its fascinating adsorption properties.Indeed,graphene has ultrahigh surface-to-volume ratio,high thermal stability,chemical properties,easily synthesis and low cost.Furthermore,it is found that the defects,vacancies,adatoms are promising approach to strengthen the gas molecules adsorption in graphene-based materials and hence graphene has a unique advantage as a sorbent material.It is well-known that pure graphene can adsorb atoms or molecules weakly.Therefore,we must modify the pure graphene to realize the excellent adsorption properties of graphene-based nanomaterials.Comparing with the traditional noble metals,metal Fe has advantages of rich raw materials,low price,high efficiency and be friendly to the environment.Therefore,we use metal atom Fe and Fe clusters to modified graphene to adsorb Sarin molecule.We explore the adsorption effects of Sarin molecules on Fe modified graphene by theoritical calculations.Diffirent adsoption propertied and stability of Sarin molecule on Fe modified graphene are investigated to explore the mechanism of Sarin molecular adsorption on graphene-based materials.It is helpful to clarify and understand identification,removal and protection of Sarin,conversion from toxic to non-toxic and other issues,and therefore provides a theoretical basis for the preparation of safe and effective chemical agent protection system.This paper mainly studies adsorption properties of Sarin molecular on pure graphene,Fe and 2Fe clusters modified graphene and 3Fe and 4Fe clusters adsorbed and calculates the adsorption energy,electron density of states and Muliken charge by using a first-principles approach based on density-functional theory.Results show that the adsorption of Sarin molecular on pure graphene is weakly physical adsorption.The introduction of Fe atoms can enhance the adsorption of Sarin molecular on graphene dramaticlly and there exists significant charge transfer between Fe modified graphene and Sarin molecular.Comparing to single Fe atom modified graphene,the adsorption of Sarin on the 2Fe cluster modified graphene is significantly enhanced.The density of states of Sarin molecular became more dispersive and moved to lower energy.The charge transfer between the Sarin molecular and the graphene increases obviously.The interaction between the Fe cluster and pure graphene depends on the shape and size of the cluster.The triangular 3Fe clusters are easily perpendicular adsorbed on the graphene surface,while 4Fe clusters adsorbed on the graphene with the tetrahedral shape.That is,with the increase of the number of Fe atoms,the adsorption capacity of the system increases and the charge transfer between Fe cluster and graphene substrate is enhanced,which results the enhanced adsorption effect.