Research On Preparation Of Functionalized Graphene And Molybdenum Disulfide And Modification Mechanism

With the development of nano science and technology,graphene and MoS₂ have attracted wide attention because of their nanometer particle size,high specific surface area and specific surface energy.Compared to conventional particles,it shows unique surface effect,size effect,quantum effect,and macro quantum tunneling effect.However,traditional prepartion methods of nanomaterials are complicated in preparation process and unfriendly to the environment so that it cannot be widely applied in practice.Therefore,the aim of this paper is to prepare in-situ functionalized nanomaterials using electrochemical method with LB104 ionic liquid as the electrolyte.The principles of ionic liquid functionalized graphene and MoS₂ were investigated by TEM,XRD,Raman,TG,DSC,FTIR,and XPS,and the working voltage and ionic liquid aqueous solution concentrations were explored for the preparation of functionalized multi-layers graphene?MLG?and MoS₂.The electrochemical mechanisms of graphene and MoS₂ were also discussed.The main conclusions are as follows:?1?When the concentration of LB104 ionic liquid has no changes,the amount and thickness of functionalized graphene and MoS₂ sheets increase with the increase of voltage.What's more,the functionalized density also increases and high-density functionalization leads to the formation of amorphous regions.?2?When the voltage remains a certain value,the thickness and functionalized density of multi-layers graphene?MLG?and MoS₂ sheets increase as the concentration of LB104ionic liquid increases.Similarly,the high-density functionalization also leads to the formation of amorphous regions.?3?The exfoliation mechanism of multi-layers graphene?MLG?:at the beginning of exfoliation,the graphite rods are exfoliated to form small graphene debris layers?or quantum dots?.Then,the amount of products increases,and the small graphene layer self-assembles to form nanospheres,or the small graphene debris layer form a nanosphere structure due to the interaction between a layer and another layer.Finally,the number of graphene nanospheres increases as exfoliation continues because of the stronger interaction between the nanospheres and it is easy to form multi-layers graphene?MLG?.?4?The exfoliation mechanism of the two-dimensional nanometer structure MoS₂:at the beginning of exfoliation,MoS₂ rods are exfoliated to form small debris layer?or quantum dots?.After a period of time,the small debris layer of MoS₂ self-assembled to form hollow nanospheres with the increase of MoS₂ products due to the interaction between the small debris layers.As the experiments continues,the number of hollow MoS₂ nanospheres increases and it is easy to form two-dimension MoS₂ sheets.?5?Electrochemical method has been used to prepare the ionic liquid-functionalized graphene and MoS₂ nano-sheets.The ionic liquid?or its functional groups?mainly exists between the nano-sheets due to the physical adsorption or chemical bonding reaction so that achieving the goal of in-situ modification.