Preparation Of Graphene-based Conducting Polymer Nanocomposites And Their Applications In Supercapacitors

In this thesis,graphene-based composites with obvious synergistic enhancement effects were synthesized by in-situ polymerization due to the high specific surface area,high mechanical strength,high electrical conductivity and excellent chemical stability of graphene,high capacitance of conducting polymer,conductivity of metal nanoparticles.The morphology,composition,and structure of the obtained various composites were characterized by using scanning electron microscopy(SEM),transmission electron microscopy(TEM),X-ray single crystal diffraction spectroscopy(XRD),X-ray photoelectron spectroscopy(XPS)and other technologies,and they were used for supercapacitors to study the electrochemical performances.The main research contents of the thesis are listed as follows:1.Graphene oxide(GO)was prepared by an improved Hummers method.Azure C(AC)and silver ions(Ag⁺)are charged small organic molecules and inorganic metal ions,respectively,and can be inserted into the GO layers.Afterwards,poly(azure C)(PAC),as a soft matter intercalant,was grown on the surface of GO layers by chemical polymerization of azure C,and then Ag NPs,as a hard matter intercalant,was grown on the surface of GO layers by chemical reduction,accompanied by the reduction of GO to r GO,resulting in the PAC/Ag NPs/r GO ternary composites.The morphology,structure and composition of the sample were characterized by SEM,TEM,XRD,and XPS.Cyclic voltammetry(CV),galvanostatic charge-discharge(GCD)and electrochemical impedance spectroscopy(EIS)ware used to test the performance of the composite as supercapacitor electrode materials.The PAC/Ag NPs/r GO composite exhibited a high specific capacitance of 576.3 F·g^-1 at a current density of 0.5 A·g^-1 and a large capacitance retention of 91.43%after 3000 cycles at the current density of 1 A·g^-1.These results demonstrate that the PAC/Ag NPs/r GO composite has the high supercapacitive performance.2.A poly(azure C)/multi-walled carbon nanotubes/graphene oxide(PAC/MWCNT/GO)composite was synthesized by in-situ polymerization,and then VC was used to chemically reduce GO to fabricate the PAC/MWCNT/r GO ternary composites.The morphology,structure and composition of the obtained composite were characterized by SEM,TEM,XRD and XPS.Results obtained from CV,GCD and EIS tests demonstrate that the PAC/MWCNT/r GO composite exhibited a high specific capacitance of 1768.77 F·g^-1 at a current density of 1 A·g^-1 and a large capacitance retention of 82.88%after 1000 cycles at the current density of 2 A·g^-1.3.A poly(azure C)/multi-walled carbon nanotubes/silver ion/graphene oxide(PAC/MWCNT/Ag⁺/GO)was synthesized by in-situ polymerization,and then VC was added to chemically reduce GO and Ag⁺at the same time to obtain a PAC/MWCNT/Ag NPs/r GO quaternary composites.The morphology,structure and composition of the sample were characterized by SEM,TEM,XRD,and XPS.Results obtained from CV,GCD and EIS tests demonstrate that the PAC/MWCNT/Ag NPs/r GO composite has a high specific capacitance of 2520 F·g^-1 at a current density of 1 A·g^-1 and high specific capacitance retention of 88.14%after 1000 cycles at a current density of 2 A·g^-1.