Graphene And Conducting Polymer Based Materials In Environment Science And Energy Storage Systems

Nowadays,a variety of dyes are used in industries,such as tex-tile,paper,printing,food,and pharmaceuticals.This causes great environmental pollution to the water system.Several techniques including chemical precipitation,ion exchange,membrane filtra-tion,adsorption,photocatalysis and electrochemical technologies have continuously been developed to pursue efficient dye removal from wastewater.Among these techniques,adsorption was found to be superior due to its low cost and simple operation procedure.In addition,recycling of the adsorbent is feasible after adsorption.Electrochemical capacitors have been widely accepted as one of the most promising electrochemical energy-storage systems and caught more attention than dielectric capacitors and batteries because of the high energy density and long cycle stability.Graphene,with two-dimensional honeycomb of carbon atoms,exhibits excellent mechanical and physicochemical properties.The high theoretical specific surface area and surface-to-volume ratio,provides more active sites for ionadsorption.It can be obtained from cheap natural graphite in large scale.These advantages make graphene a promising adsorbent.Herein,a simple,fast route for the reduction of graphene oxide（GO）using Ti powder as a reducing agent under household microwave assistance is developed.Hydrolysis was followed to synthesize reduced graphene oxide/titania（MrGO/TiO₂）.The reduction of GO was traced and further characterized by UV–visible（UV–vis）absorption spectroscopy,thermogravimetric analysis（TGA）,X-ray diffraction（XRD）and laman spectroscopy.XRD and TGA were also used to analysis the crystal structure and the weight content of TiO₂.Transmission electron microscopy（TEM）and scanning electron microscopy（SEM）were used to analysis the morphology of the binary composite and the distribution of TiO₂.Methylene blue（MB）was used to study the adsorption performance of MrGO/TiO₂,UV–vis was used to measure the adsorbent capacity.After that,the products were centrifuged,rinsed with distilled water.The recycling of MrGO/TiO₂ was achieved by photocatalytic degradation of MB catalyzed by Mr GO/TiO₂itself。 Mpreover,MnMoO₄ was prepared by chemical precipitation.A binary composite polypyrrole@MnMoO₄ was facilely prepared via in situ oxidative polymerization of monomer in the presence of MnMoO₄ nanorods.The MnMoO₄ nanorods were wrapped by a layer of polypyrrole（PPy）and formed a core-sheath structure which embedded in PPy matrix.The prepared PPy@Mn MoO₄ composite was characterized by XRD,IR,SEM and TEM spectroscopy.Its electrochemical performance was measured by voltammetry（CV）,Galvanostatic charge/discharge（GV）and the electrochemical impedance spectroscopy（EIS）in a three-electrode system and two-electrode system.CoMoO₄ was also prepared by a hydrothermal mehtod.A binary composite polypyrrole@CoMoO₄ nanorod was facilely prepared via in situ oxidative polymerization of monomer in the presence of CoMoO₄ nanorods.The CoMoO₄ nanorods were wrapped by a layer of polypyrrole（PPy）and formed a core-sheath structure.The prepared PPy@CoMoO₄ nanorod was characterized by XRD,IR,SEM,and TEM spectroscopy.Its electrochemical performance was measured by voltammetry（CV）,Galvanostatic charge/discharge（GV）and the electrochemical impedance spectroscopy（EIS）in a three-electrode system and two-electrode system.