The Research Of Electrical And Electrochemical Properties Of Graphene By Structure Regulation

Graphene has a very wide range of applications due to its unique electrical,mechanical properties and high specific surface area（SSA）.The structure regulation of graphene is crucial for the application of graphene.Therefore,we control the macroscopic structure of graphene to ensure the better electrical properties and study the application of graphene in the field of electricity,control the microstructure defects of graphene to regulate the electron distribution on the surface of graphene,and study it in the field of electrochemistry.The main works are as follows:1.The macrostructure of graphene was regulated by γ-ray method to yield the graphene sponge（GS）with ultra-low density(<5 mg.cm^-3),high conductivity(>0.24 S m^-1),excellent mechanical（the maximum stress still remains 76%after 800 cycles under the strain of 50%）and electrical（the conductivity change in the 20 cycles are almost same under the same stress）stability.What’s more,the stress in the same strain（4.2 kPa in the strain of 80%）is less and the sensitivity(1.03 kPa^-1)in the lower stress region（0-0.5 kPa）is higher than most reported literature.The ultra-low stress and high sensitivity make it possible to detect the pressure signals precisely as low as 10 Pa.To further illustrate the lower stress to the sensitivity of sponge in the field of pressure sensor,The CNT was added to the sponge（GS-n wt.%-CNT,n depend on the mass fraction of CNT）,and the sensitivity decreased to 0.81 kPa^-1 which can only detect 25 Pa.2.The microstructure defect of graphene model electrode was regulated by Ar-plasma treated method and the bulk defect density or structure was controlled by the Ar-plasma treated time by 7 s in every step.The current density increased from 11.6 to 42 uA cm^-2 in the potential of-0.6 V with the defect density varied from 0.23 to 5.04 x 10¹¹ cm^-2.However,the current density decreased from 42 to 34.8 uAcm^-2 as the defect density increased from 5.04×10¹¹cm^-2 to 6.02×10¹¹cm^-2,the results above were repeated 7 times which get the same result.The defects structure with different states(nd<5.04×10¹¹cm^-2,nd>6.02×10¹¹cm^-2)were measured and we get a conclusion that the Thrower-stone-wales defects（55-77）can improve the materials electrocatalytic activity toward the ORR own to the improvement of the density of states（DOS）,and the vacancy defects can reduce the catalyst activities own to the decline of the 55-77 structure.