Preparation And Characte Rization Of The Electrochemical Reducation Of Graphene Modified Electrode And Its Electrocatalysis Toward Nitro Componds

Graphene is a 2D flat sheet materiala that is composed with a single atomic layer. It is formed by SP2 hybrid orbitals in a covalent bond by carbon atoms combined with each other, forming rules the six-party ideal two-dimensional crystal. Due to its unique structure, it has excellent physical and chemical properties, and widely applied in basic research and potential applications such as nano composite materials, sensors, batteries, super capacitor, hydrogen storage, etc. For its prepration, the traditional method employed is mechanical stripping, but for the reason that low productivity, high cost and not conducive to mass production, it was not chosen by researcher. In recent years, chemical reducing method was employed by more and more researchers for preparing graphene, but it is difficult to remove completely reducing agent, and the reducing agent can introduce pollution, so the electronic properties of graphene can be weakened, environmentally unfriendly, and limiting the further application of this method. As an effective means, the electrochemical technology, not only green, pollution-free, but also can change the Fermi level of the electrode material surface via adjusting various properties of the material and then make development, expand the scope of application of the material. In this thesis, the electrochemical reducing graphene oxide(ERGO) modified electrode surface by one-step electrochemical reduction method was proposed using cyclic voltammetry(CV). The prepared modified electrodes were characterized by scanning electron microscopy(SEM), Raman spectroscopy(Raman), X-ray photoelectron spectroscopy(XPS), cyclic voltammetry(CV), differential pulse voltammetry(DPV), electrochemical impedance spectroscopy(EIS) and so on. the electro-catalytic mechanism of the prepared ERGO modified electrodes toward nitrite and nitrophenol isomers by CV, DPV and chronoamperometry techniques.The main contents are as follows:Chapter 1. The electrochemical properties of the ERGO modified electrodes, and its electrocatalysis toward nitriteUsing one-step electrodeposition technology, three ERGO modified carbon electrodes substrate was successfully prepared. The prepared modified electrodes were characterized by SEM, Raman, XPS, CV, DPV, EIS, etc. The results show that the electrochemical deposition of ERGO films is evenly distributed on three substrate surface, resulting increase the surface area of three modified electrode s, effectively enhance the electron transport properties of electrode interface. The results showed that the electron transfer rate of potassium ferricyanide probe molecules on ERGO modified glassy carbon electrode, pyrolytic graphite electrode and carbon paste electrode are corresponding bare electrodes? 4.0, 3.3 and 2.3 times.And the electron transfer rate of ERGO modified glassy carbon electrode sodium nitrite target molecule, pyrolytic graphite electrode and carbon paste electrode are corresponding bare electrodes? 1.4, 7.2 and 24.0 times. ERGO modified glassy carbon electrodes were suggested that they have high electro-catalytic oxidation toward nitrite. A new way of thinking and methods was provided toward explore structure-activity relationship ERGO class electrochemical sensor.Chapter 2. The electrochemical response of graphene film modified pyrolytic graphite electrode toward nitrophenol isomerThe electrochemical reduction of graphene oxide(ERGO) films modified pyrolytic graphite electrode(GE) was prepared by one-step electrochemical reduction method. The ERGO modified GE was characterized by SEM(EDS), CV, DPV, EIS, etc. The electron transfer properties of modified electrode interface was enhanced. The electrochemical reduction mechanism of ERGO modified electrode toward nitrophenol isomer was studied by the ultraviolet visible spectrum(UV-Vis) and chronoamperometry. The results showed that the electron transfer rate of ERGO modified electrode toward nitrophenol isomer is increased using CV, DPV. The electrocatalysis of ERGO modified electrode was sensitiver by K inetic studies.The study is significant toward designing and developing the functional electrochemical reduction of graphene sensor.