| At present,there are many researches on the growth of graphene on Cu Ni metal films by CVD,but few on the growth of graphene on micro patterned Cu Ni films.The reduction of metal film thickness can reduce the cost,the total processing time and the manufacturing cost.At the same time,the metal electrode with nanometer thickness can be compatible with the standard MEMS and nano electromechanical equipment,but the dehumidification phenomenon of the solid film surface limits the reduction of the metal film thickness.In this thesis,the graphene monolayer was prepared on the surface of the pre patterned Cu Ni electrode with thickness of 410 nm by atmospheric pressure chemical vapor deposition.The results show that when the total thickness of the metal film is 410 nm(the thickness of copper/ nickel is 340 nm and 70 nm respectively),adjusting the annealing and growth process can effectively increase the number and integrity of graphene layers by prolonging the time of methane gas entering into the graphene growth process.In addition,the electrochemical properties of graphene / Cu /Ni composite electrode were studied,the corrosion resistance of the electrode was discussed,and the relationship between the growth time,number of layers and integrity of graphene and its corrosion resistance was explored.The electrochemical polarization curve confirms that the sample with graphene growth time of 8 min has the highest polarization resistance and the lowest corrosion current among these samples.EIS test results imply that the interface resistance between copper and electrolytic solution gradually increases as the graphene growth time increases,as well as the corrosion resistance.With the extension of graphene growth time,the interface resistance between electrode and electrolyte increases with the increase of graphene layer number and coverage,and the corrosion resistance also increases gradually High.In the low frequency range,the impedance modulus of the electrode covered with uniform graphene and the electrode covered with 2-3 layers of graphene is significantly higher than that of the electrode without graphene.With the increase of the number and coverage of graphene layers on the electrode surface,the impedance mode value | z| of the samples in the low frequency range is significantly higher than that of the samples in other growth times.The corresponding composite electrode is more corrosion-resistant and the graphene protective layer is more stable.But if the graphene grows incompletely or has defects,the metal in the corresponding part will be corroded more quickly.The first principle simulation results show that the adsorption energy of oxygen on the surface of copper without graphene is lower than that on the surface of copper without graphene.Graphene can effectively prevent the adsorption of oxygen on the surface of copper,which reducing the corrosion rate.However,However,the defect density and coverage of graphene layer on the surface of the electrode also affect the adsorption energy of oxygen on the surface. |
