The Fabrication And Analysis Of Graphene-based Nanocomposites And Their Electrochemical Property Investigation

In this paper, we studied the electrochemical behavior of graphene-based nanocomposites. Several graphene-based nanocomposites were successfully synthesized and their morphologies and crystalline structures were characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM), Fourier transform infrared spectra (FTIR), X-ray photoelectron spectroscopy (XPS), Raman spectroscopy, energy-dispersive X-ray spectroscopy (EDX). We studied the nanocomposites in the ethanol fuel cell, photocatalytic degradation, electrochemical analysis application. The major contents are described as follows:1. A new non-noble electro-catalyst for DEFCs was prepared by a facile, economic and environmentally friendly method. The synthesized materials Ni-Co/graphene (GE) and Ni/GE are characterized by X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), energy-dispersive X-ray spectroscopy (EDX), transmission electron microscopy (TEM) and electrical analysis technology. The electrocatalytic properties of the two materials for ethanol oxidation in alkaline medium are investigated by cyclic voltammetry (CV), chronoamperometry and Tafel plot. The rate constant (ks) and charge transfer coefficient (a) are calculated for the electron exchange reaction of the modified GCE. Compared with Ni/GE catalyst, Ni-Co/GE has the higher electro-activity and better stability for ethanol oxidation.2. The Cu2O/SnO2/GE and SnO2/GE nanocomposite photocatalysts were prepared by a simple wet-chemical method. The synthesized materials are characterized by XRD, TEM, FTIR, scanning electron microscope (SEM), Raman spectroscopy, XPS and UV-vis. The photocatalytic efficiency of catalysts were evaluated by degradation of pendimethalin under visible light irradiation (λ,>420nm) and the mechanism of photocatalytic reaction is proposed based on the energy band theory and experimental results. We found that GE composite materials exhibite better photocatalytic activity than pure Cu2O/SnO2and SnO2. 3. The SnO2/GE/CNTs nanocomposite photocatalyst was prepared by a simple and environmentally friendly wet-chemical method. The material was characterized by FTIR, XRD, EDX and TEM. The electrochemical behaviors of nanocomposite and the performance of the electro-catalytic oxidation for NO2were studied by CV. We prepared the modified electrodes and developed analysis method of NO2-based on pulse voltammetry (DPV) on this basis.