Preparation And Characterization Of Reduced Graphene Oxide/Conducting Polymer

The graphene/conducting polymer composites, as an active research field of conducting polymer nanocomposites, could be promising materials for widely applications, such as energy storage and conversion devices, sensors, electric devices,photovoltaic cells and drug carriers because of its high specific surface area, good electrical conductivity, strong mechanical properties and excellent thermal stability and so on. The traditional fabrication methods of the graphene/conducting polymer composites have many intrinsic deficiencies, such as the limited performances of the composites, hard removing of the residual ions and the surrounding pollution. Therefore,this paper mainly focuses on the RGO/PEDOT composite prepared by using GO as chemical oxidant and graphene precursor during the in-situ polymerization process.Meanwhile, the electrochemical and gas sensing properties of the RGO/PEDOT composites were studied. The main contents are as follows:1. The RGO/PEDOT composites were facilely synthesized at hydrothermal conditions by using GO as a chemical oxidant and graphene precursor. The composites were characterized by Ultraviolet-visible (UV-vis), Fourier transform infrared (FTIR)spectroscopy, Raman spectroscopy, Scanning electron microscopy (SEM), X-ray energy spectrum (EDS), Transmission electron microscopy (TEM) and Photoelectron spectroscopy (XPS) methods. The results indicate that the oxygen-containing functional groups on GO surface effectively catalyzed the EDOT monomer and initiated EDOT monomer polymerization. The particle shape of obtained PEDOT was deposited on the plane of RGO, and a PEDOT-coated lamellar composite structure was obtained.Furthermore, the results indicate that the reduction degree of RGO in composites was more complete than that of pristine RGO be reduced by hydrothermal method.2. Based on the characterization and theoretical analysis, we propose a mechanism for the polymerization of conducting polymer, which is based on oxidative functional groups to induce free radical polymerization, and reveal the preparation mechanism of RGO/PEDOT composite nanomaterial. It is believed that the hydroxyl and epoxy groups on GO surface can be used as initiating active sites, and the EDOT monomer is induced as the initial free radical. Then, the deoxidization process of GO and the dehydrogenation procedure of EDOT promote mutually, after chain initiation, chain growth and chain termination, which results in the formation of the RGO/PEDOT composite.3. The electrochemical performance of RGO and as-prepared RGO/PEDOT with different mass ratio were investigated. Compared with pure RGO, the energy storage characteristic of RGO/PEDOT composite films, preparing by 6ml GO dispersion and 60?l EDOT monomer, which were obviously improved. The areal capacitance is up to 33.10F/cm3 at the current density of 0.053A/cm3, which is much higher than pristine RGO (6.30F/cm3).4. The sensitivity of RGO and RGO/PEDOT composites to NH3 were investigated.The results indicate that RGO/PEDOT composite films has good linearity response to NH3 in the low concentration range of 2.5-20ppm, and its linear fitting coefficient (R)is 0.94847. The sensitivity of RGO/PEDOT is superior to pure RGO because of the synergistic effect between RGO and PEDOT, results in improved the sensitivity of the composite films.