Preparation And Catalytic Properties Of Graphene Modified Electrode

Due to its unique structure and properties, graphene has attached muchattention in the fields of chemistry, material science and so on. In this thesis, wemainly focused on synthesizing graphene oxide, preparing graphene modifiedelectrode, using the as-prepared graphene modified electrode for Pb²⁺ detection,and characterizing the electrocatalytic activity of graphene for O2reduction andtetrachlorophenol oxidation.1、Preparation and characterization of grapheneoxide.The graphene used in this thesis was synthesized according to the modifiedHummers’method and characterized by XRD, Raman, AFM, TEM, SEM. Resultsshowed that the products were single layer or multilayer graphenes with a crimpedthin layer structure.2、Determination of lead ions with graphene–poly-L-lysinemodified glassy carbon electrode.A graphene-poly-L-lysine modified glassy carbonelectrode was fabricated by a three-step process, i.e. electropolymerization ofL-lysine, adsorption of graphene oxide and then electrochemical reduction ofgraphene oxide. Raman spectra suggested that the graphene oxide on the electrodesurface could be partially reduced to graphene during the electrochemical reductionprocess. The modified electrode showed a good sensitivity and selectivity for Pb²⁺detection in the concentration range of1.0～5.0^10-6mol/L.3、Graphene modifiedelectrode for oxygen reduction and tetrachlorophenol oxidation.The graphene–Poly-L-lysine modified GC electrode and the graphene-Nafion modified GC electrodewere used for electrocatalyzing O2reduction and tetrachlorophenol oxidation. Bothgraphene modified electrodes showed good electroocatalytic activity, and in which,the graphene–Poly-L-lysine modified GC electrode is better. The electroocatalyticactivity of graphene modified electrode was also found to be similar as theelectroocatalytic activity of La₂NiO₄modified electrode.