The Preparation And Electrochemical Application Of Poly Ionic Liquids/Graphene Based Nanomaterials

Graphene,which is a single layer of carbon atoms arrayed in a repeating,honeycomb-like arrangement,is the thinnest material to date.By virtue of its excellent properties,such as large specific surface area,well biocompatibility and superior mechanical property,this kind of intriguing nanomaterial has aroused great interest in the fields of sensors,electrochemistry and materials science.However,graphene is hydrophobic and tends to form agglomerates due to the van der Wals interactions and strong ?-? stacking,which limit its applications,especially in the field of electrochemistry.It has been found that graphene-based nanocomposites can be effective in improving the solubility of graphene.In addition,graphene nanocomposite based modified electrode also exhibited enhanced electrochemical performance because of its excellent properties.Herein,polymeric ionic liquid-graphene nanocomposite was synthesized and utilized for the fabrication of nevel modified electrode for the selective detection of dopamine and construction of series of functionalized electroactive graphene.The main research work of the thesis are summarized as follows:1.Novel functionalized graphene nanosheets,PIL(Br)modified graphene(Poly(ViEtIm+Br-)-GP)was synthesized via the ?-? interaction between graphene nanosheet and the polymeric ionic liquids.The morphology and structure of the synthesized nanocomposite was characterized by TEM,UV-vis and FT-IR.The graphene based nanocomposite was then utilized to fabricate Poly(ViEtIm+Br-)-GP/GC electrode.The electrochemical behavior of the modified electrode toward the oxidaton of dopamine(DA)was investigated.The modified electrode exhibited a wide liner response for DA with AA and UA(give out the formal name of these two substances)coexisting.The concentration range of Poly(ViEtIm+Br-)-GP/GC electrode toward the oxidation of AA was 0.7?M-95?M,and the detection limit and sensitivity were 0.23 ?M and 41.29 A·cm-2·M-1(S/N = 3)respectively.2.Based on the anion exchange property of modified polymeric ionic liquid,various electroactive graphene was fabricated by the immobilization of Fe(CN)43-and PWA anions onto Poly(ViEtIm+Br-)-GP.FT-IR and cyclic voltammogram measurements were employed to characterize the as prepared functionalized graphene.The electrochemical behavior of the Fe(CN)63-/Poly-IL/GP/GC and PWA/Poly-IL/GP/GC modified electrodes were also investigated.The experimental results demonstrated that the Fe(CN)63-/Poly-IL/GP/GC modified electrode exhibited good electrochemical catalytic performance towards AA with a linear range from 0.1 to 6.2 mM,together with a high sensitivity of 31.04 A·cm-2·M-1.As for the PWA/Poly-IL/GP/GC modified electrode,it exhibited excellent catalytic performance for the sensitive detection of potassium bromate with a linear range from 0.1 mM to 1.4 mM with a sensitivity of 41.75 A·cm-2·M-1.