Preparation Of Carbon Based Nanocomposites And Their Application In Supercapacitor And Electrochemical Sensor

Owing to the particularity nanostructures of nano materials,the materials have large specific surface area,strong adsorption ability,as well as good biological compatibility,and they showed excellent electrochemical performance,so in the field of electrochemical sensor,supercapacitors and other fields nanomaterials have been widely used.In recent years,some enzymes,transition metals,transition metal oxides and conductive polymers nano materials are widely used in electrochemical fields.With the development of nano materials research,nano material alone due to agglomeration would hinder the electronic transmission,reduce the material surface,and the electrochemical properties of nanomaterials,therefore to seek suitable nanocomposite is a must.Carbon-based materials such as graphene,porous carbon were commonly used to load onto the supported material.Graphene has a large specific surface area,good electrical conductivity,well biological compatibility and didn't have variable valence state advantages of redox reaction to occur.As for the porous carbon,they were easy-get sources with large specific surface area and low cost.This paper focuses on carbon based composite materials modified by in situ growth or electrochemical reduction method to load nano materials,and constructed the whole composite electrode.It can improved poor performance of single nanometer material dispersion,what's more,as construction of one electrode,without adhesive materials,it can effectively avoid the interference of adhesive for electrochemical performance.The works are as follows:1.In the first work,the pre-treated carbon paper were treated by electrochemical method using K2CO3,KNO3,respectively.These two step would peeled commercial carbon paper electrochemical by a mildly way.Then the gotten FEG were detected by RAMAN spectral and scanning electron microscope?SEM?,confirmed that carbon paper is successfully peeled off and the typical layered graphene fold structure can be observed,and then in situ growing Fe3O4 on the surface of carbon cloth,tested by constant current charge discharge test,the specific capacitance of Fe3O4 /FEG were 316.07 F g^-1 at a current density of 1 A g^-1,we also found that when the surface were treated by diazonium salt,the specific capacitance of functional Fe3O4 /FEG were 470 F g^-1 at a current density of 1 A g^-1,showed a good performance.2.Based on the first work,we found the electrochemical method to peel carbon paper graphene is time-consuming and the final gotten graphene were not uniform.So in my sencond work,a simple and large-scale strategy to prepare flexible graphene tape electrode?GTE?was proposed based on Geim and Novoselov's method,and we constructed two kinds of glucose sensor?Ni-CoNPs/GTE and glucose GOD/AuNPs-CHIT/GTE?based on this tape electrode,the Ni-CoNPs/GTE showed a linear range of 0.6 mM to 260 mM?R = 0.992?and 1.36 mM to 5.464 m M,?R=0.996?? The linear range of GOD/AuNPs-CHIT/GTE towards glucose were:0-14.0 mM?R=0.992?,the detection limit was 0.202 m M,the sensitivity was 9 ?A m M-1 cm-2? The results showed both of the two kinds of glucose sensor has good electrochemical performance,and the two sensor were also be used for the detection of actual samples.These results demonstrated that three-dimensional porous flexible graphene conductive electrode have the potential in the application of electrochemical sensor and biosensor.3.In the third work,we use melamine foam as the precursor,obtained the melamine foam porous carbon materials by the calcination step,and then the graphene solution were dropped in carbon foam to obtain graphene / carbon foam composite material,and the polyaniline were in situ grown on the graphene / carbon foam to get Polyaniline / carbon foam?CC-GO-PANI?by chemical oxidation method,the CC-GO-PANI showed high specific capacitance(specific capacitance of 1870 F g^-1 at the current density of 1 A g^-1)and good cycling performance(charge discharge cycle 5000 times at 5 A g^-1,the specific capacitance decreases to 95%).The materials of this work were easy to get,and the combine of graphene and polyaniline can promote the transport of the electron which result to a better capacitance and good cycle performance.The composite materials have potential applications in the field of super capacitors.