The Study On The Preparation Of Graphene /Conductive Polymer Composites And Its Application In Electroanalytical Chemistry

The dissertation is mainly focused on the application of graphene and conducting polymer-poly（3,4-ethylenedioxythiophene）（PEDOT）in electrochemistry.The special structure of graphene endows its excellent performance and also extends its application in many field.Graphene-based composite have broad application in many fields and have become the most potential functional materials in 21 st century.PEDOT has many advantages such as good conductivity,low oxidation-reduction potential,good thermo chemical stability,easy film formation and good biocompatibility.In this work,we prepared electrochemical biosensors with good specificity and high catalytic efficiency via the electrostatic layer by layer self-assembly technique,the pulse potentiostatic method and the double metal doping technique.This study deepens the application of graphene /conductive polymer composites in electrochemistry.The main studies are as followings: 1.Preparation of（PEDOT: PSS）₅/（PDDA-G）₆/GCE by electrostatic layer by layer self assembly and its detection for H₂O₂We prepared poly（dimethyl diallyl ammonium chloride）（PDDA）functionalized graphene（PDDA-G）.The（PEDOT:PSS）₅/（PDDA-G）₆ composite film were made by self-assembly by the electrostatic attraction between positively charged PDDA-G and negatively charged PEDOT:PSS.（PEDOT:PSS）₅/（PDDA-G）₆/GCE showed good electrocatalytic activity toward the reduction reaction of H₂O₂.The results indicated that the biosensor showed a wide linear range from 0.02 μM to 0.47 mM and a low detection limit of 6.7 nM.2.Preparation of PtNPs/{PDDA-G/PEDOT:PSS}_n/GCE and its catalytic oxidation toward methanol（PEDOT: PSS/PDDA-G）n composite film was obtained on the basis of the above experiment.Then the（PEDOT: PSS/PDDA-G）n was used as a novel catalyst for loading Pt nanoparticles in situ.The composite film was characterized by UV-Vis,XRD,XPS,and SEM.The catalytic performance of PtNPs/{PDDA-G/PEDOT:PSS}_n/GCE toward methanol oxidation was studied by electrochemical method.The results showed that the catalyst exhibited good electrocatalytic activity toward methanol oxidation and high tolerance to carbon monoxide poisoning.The synergistic effect of PDDA-G and PEDOT:PSS is beneficial to the catalytic oxidation of methanol,which is mainly attributed to the excellent electronic conductivity of graphene and PEDOT.3.One step synthesis of PEDOT-rGO composite based on pulse potentialstatic method and its detection for glucoseThe PEDOT-rGO composites were prepared by one step pulse potentiostatic method.The method is simple,rapid,and does not use toxic reducing agent.The π-π* interaction and the hydrogen bonding between graphene and aromatic ring of EDOT monomer not only promoted the polymerization but also enhanced the film forming ability of the PEDOT-rGO composite film.Then,the Ni nanoparticles were deposited on the surface of the composite modified electrode.The catalytic performance of NiNPs/PEDOT-rGO/GCE toward the oxidation of glucose was studied by electrochemical method.The experimental results showed that the electrochemical response of glucose showed a good linear relationship in the concentration range of 2 μM⁵8 mM and a low detection limit of 0.7 μM.4.Preparation of Au-PtNPs/PEDOT-rGO composite by liquid-liquid interface polymerization method and its electrocatalytic ability toward methanol oxidationAu-PtNPs/PEDOT-rGO composite was prepared by liquid-liquid interface polymerization method.The catalytic ability of the Au-PtNPs/PEDOT-rGO modified glassy carbon electrode toward the electrochemical oxidation of methanol was studied.The results showed that the Au-PtNPs/PEDOT-rGO had good catalytic performance and resistance to carbon monoxide oxidation.