Preparation And Application Of Electrochemical Senors Based On Graphene Composites

Graphene,as a two–dimensional plane material which consists of C atoms,has good thermal properties,mechanical properties and electrical properties.The derivatives of the graphene mainly include graphene oxide?GO?and reduced graphene oxide?rGO?,in which the surface of them contains rich oxygenous functional groups those can combine with other composites to form graphene composites.Graphene composites modified electrodes have fast electron transfer rate,low consumption,the advantages of low detection limit,and excellent stability.Several composite materials were prepared based on graphene and applied to the electrochemical detection.The experimental results showed that the graphene composite materials have good application prospect in the electrochemical sensor.The research content mainly contains the following several aspects:1.Synthesis of Co@Fe₂O₂CO₃-rGO composite modified electrode by useing one–step electrodeposition method.The SEM,TEM,XRD and XPS experiments were used to characterize the materials.Compared cyclic voltammetric response of H₂O₂ of different electrode materials,then optimized the reduction potential of H₂O₂.The linear range and detection limit of the Co@Fe₂O₂CO₃-rGO modified electrode to detect H₂O₂ were0.5?956?mol/L and 0.4?mol/L,respectively.To a certain amount of interference substances,glucose,ascorbic acid and uric acid had no significant effect of H₂O₂determination,it can be said that the modified electrode has good selectivity and anti-interference capacity.2.By using the multi–potential steps method to prepare of gold/reduced graphene oxide?Au/rGO?modified electrode and utilized the modified electrode to detect Fe³⁺.The SEM and electrochemical method were used to characterize the modified electrode.The results showed that the multi-potential steps method can be used to the preparation of graphene composites.The 1-?2-pyridylazo?-2-naphthol?PAN?was used as the complexing agent.The concentration of PAN,accumulation potential and accumulation time were optimized in the experiment,and the linear range of Fe³⁺determination got by using the composite modified electrode.In the meantime,the detection results of real samples were reliable.3.Preparation of graphene oxide–polyaniline composite material through the electro–polymerization method.The morphology and electrochemical characterization were used to characterize the composite.Results showed that the polyaniline modified to the surface of graphene oxide successfully which has dense fibrous morphology.The modified electrode has good electrochemical capacity and has obvious electrochemical response to Pb²⁺,so that the composite has a good application prospect in electrochemical sensor.