Preparation Of Novel Nanocomposite And Their Electrochemical Research

Nanomaterials have special structure, which results in series of interesting physicaland chemical properties. The application of nanomaterials has involved innanoelectronics, nanochemistry, catalysis, biosensing, environmental detection,medicine and so on. This thesis is aim to develop and design some highly selectiveand sensitive electrochemical sensor by mean of the combination of nanomaterials andelectrochemical methods. Some new nanomaterial-modified electrode have beenprepared for investigating their electrochemical response characteristics toward somefuel and environment pollutants. Some selective and sensitive methods have beenestablished for their application in fule cell and environmental monitoring. Meanwhile,these researches are helpful to select some suitable carrier to construct some highlyselective chemical sensors based on biomolecule and supramolecular recognition. Thethesis can be divided into three chapters.Chapter I: we present a facile carbon radicals reaction procedure by the thermaldecomposition of azodiisobutyronitrile to prepare the uniform carboxylic sodiumfunctionalized graphene and a chemical reduction method to functionalize CS-G withhighly dispersive Ag NPs using NaBH4as reductant. Most importantly, the resultsshowed that the hybrid material shows a good electrocatalytic activity to NB, DNT,TNT, which is reduced large overvoltage and enhanced current signal. It is proved thatthe determination of nitroaromatic compounds with a lower detection limit of NB,DNT, TNT of0.60ppm,0.21ppm,0.45ppm, respectively. Cathodic peak current ofNB, DNT, TNT at modified electrode is well linear with its concentration in the rangeof1-70ppm. The modified electrode also exhibits good stability and reproducibility.Chapter II: A easy carbon radicals reaction procedure was proposed to functionalizegraphene with uniform carboxylic sodium groups （CS-G）. Carboxylic sodium groupson functionalized graphene provided binding sites for anchoring precursor metal ionsto form highly dispersive Pt-Pd catalysts by the in-situ electrochemical reductionmethod. Pt-Pd bimetallic catalysts are widely used in fuel cells because of some advantages, which the synergetic effect of alloys can overcome poisoning effect ofadsorbed CO. Most importantly, the resultant Pt-Pd/CS-G/GCE shows much highercatalytic activity and more long-term stability towards the electrooxidation ofmethanol than that of Pt-Pd/G/GCE and Pt/CS-G/GCE, which the synergetic effect ofalloys can overcome poisoning effect of adsorbed CO and the Pt-Pd bimetalliccatalysts can improve catalytic activity due to more available surface active sites.Chapter III: The glassy carbon electrode was modified with phenyl-mesoporousSiO₂（Ph-MCM-41） and then grafted successfully with4-aminobenzoic acid usingelectrochemical modification technology of “electropolymerization”. The obtainedelectrode was also modified with highly dispersed silver nanoparticles on thePh-MCM-41（Ag/Ph-MCM-41） by the electrodeposition technology. Ag/Ph-MCM-41have used to modify glassy carbon electrode for the electrochemicalinvestigation of nitrobenzene （NB）. The results show that modified electrode exhibithigh sensitivity and good response to ultratrace NB molecules, which is reduced largeovervoltage and enhanced current signal.