The Functionalization Of Graphene And Its Study Of Analysis And Application Of Electrochemical Performance

The special structure of graphene determines its unique properties, such as low resistivity, large specific surface area, relatively high carrier mobility and so on, one of the most surprising properties is the very specific electrical property, which makes graphene become the most ideal material of modified electrode in electrochemical sensor, it has good optimization ability for the selectivity, stability, detection limit,linear range of the electrochemical sensor. But graphene itself easily reunites, which makes its original electrochemical performance of development and application be limited. Thus developing the composite graphene materials has become an important way to maintain and expand its electrochemical performance.Quantum dots are known as semiconductornanocrystals, they are also called artificial atoms, whichwas similar to the energy level separation structure of the independentatomic. And the quantum dot composed of the IIA, VIA and VIII elements is widely used due to the quantum confinement effect with unique electrical property, the diameter is 2~10 nm. Because of the compositionof a conductor or semiconductor materials which make it havestrong conductivity and small size structure which make it possesslarge surface effect to adsorb electroactive substances,these performances make it become one of the best materials to functionalize GR.Surfactants, due to theirs molecular with parents, it can effectively prevent the phenomenon of the aggregation of graphene and graphene is well dispersed in water.So it is used as functional materials for the functionalization of graphene and functionalization of grapheme for making sensors. Compared with graphene, the functional graphene can significantly improve the analysis of sensitivity, selectivity and reproducibility, thus it is a good dispersant and functional reagent for nanomaterial preparation.Preparing a electrochemical sensor which is sensitive to the response of CC as a target, he preparation, functionalization of graphene, functional graphene electric catalytic performance and analysis of the applications of functional graphene to CC was discussed respectively in this paper. Specific research contentsare as follows:1. The Hummer method was adopted to prepare graphene oxide andspectroscopy and X-ray diffraction infrared analysis was used to characterize graphene oxide. And we used chemical method and electrochemical method to reducethe graphene oxide, respectively, and then the tworeductionmethods of graphene's electrical catalytic properties were compared. Finally, we determine the optimum reduction method of grapheneoxide.2. Using the hydrothermal method to prepare semiconductor nanocrystals-cadmium telluride quantum dots, which was regared as a raw material to functionalize graphene, and electricity chemistry methods were used to characterize the functional graphene(CdTe/GR), and the electrocatalitic of the modified electrochemical sensor prepared by CdTe/GR) were studied.3. Choose to use the common surfactant- cetyl trimethyl ammonium bromide and twelve alkyl sodium sulfate to functionalize graphene, and compare the dispersion of graphene and functionalgraphene, at the same time, the electrochemical method such as cyclic voltammograms and impedance analysis was adopted to characterize functionalgraphene.Finally thedifference of different surfactant functionalization of graphene's electrical catalytic performance to CC was discussed. Then the optimum functional reagent was determined as cetyl trimethyl ammonium bromide.4. We researched theperformance of electrochemical sensor of graphene functionalized with cadmium telluride quantum dots and hexadecyl trimethyl ammonium bromide and optimized the analysis conditionof catechol. Under the optimized conditions, the sensor was applied for the detection of CC in the actual samples. Based on CdTe QDs/GR nanocomposite, a green electrochemical sensor was fabricated for sensitive detection of CCl, The linear range of catechol was from30?mol/Lto1000 ?mol/L with a detection limit of 18.19 ?mol/L(S/N = 3). The recovery was founded to be in the range of 98.35 % ~ 104.96 %.The sensor based on CTMAB/GR nanocomposite was applied to the detection of catechol, the concentration of CC in 5?mol/L to 1000 ?mol/Loxidation and reduction peak current all had good linear relationship, and with the oxidation peak of quantitative, the detection limit was 2.92 ?mol/L and with the oxidation peak of quantitative, the detection limit was 2.44 ?mol/L, the recovery was founded to be in the range of92.70 %~101.80 %. Moreover, these sensors could be used for the detection of CC in real samples with satisfactory results.And the oxidation mechanism of catechol has been discussed preliminarily.