The Preparation Of Graphene Coatings By Electrochemical Methods And Anti-corrosion Performance

With the development of the marine economy,steel and iron materials are used widely in marine environment.However,the steel will undoubtedly be corroded in marine environment,which could cause huge economic loss.Therefore,one of the most effective ways to solve the problem of steel corrosion in marine environment is exploiting high protection performance coatings.In this paper,C750 and M15 graphene nanosheets were doped with H~+,and then electrophoretic deposition and cyclic voltammetry were used to deposite graphene coatings on Q235 steel,respectively.The physical properties of the graphene coatings were characterized by field emission scanning electron microscope(FE-SEM),X-ray diffraction(XRD)and Raman spectroscopy(Raman).The anti-corrosion properties of the graphene coatings on Q235steel substrates which made in different electrolyte concentrations was investigated by electrochemical methods.The research progression in the thesis are as follows:(1)The problem of dispersing graphene nanosheets by organic solvent has been solved,and the optimal ratio of the solvent is H2O:NMP:ACN=1:3:6.(2)The technological parameters for the preparation of the graphene coatings on Q235 steel by electrophoretic deposition have been optimized and the optimal technological parameters are 30?constant temperature,constant voltage 80V and 5min deposition time.(3)The crystal structure of C750 graphene coatings which made by electrophoretic deposition and cyclic voltammetry respectively and M15 graphene coatings which made by cyclic voltammetry on Q235 steel substrate have not been destroyed.(4)When the concentration of H~+-C750 in the electrolyte is 1.6mg/mL,the anti-corrosion effect of the C750 graphene coating prepared by electrophoretic deposition is much better than others,and also better than that obtained by cyclic voltammetry.When the concentration of H~+-M15 in the electrolyte is 0.75mg/mL,the anti-corrosion properties of the M15 graphene coating prepared by cyclic voltammetry is the best.(5)The binding property between coating/matrix could be improved by using the dopamine to modificate the surface of Q235 steel.When the concentration of H~+-C750 in the electrolyte is 1.8mg/mL,the anti-corrosion properties of the coating is much better than others.Those research progression would provide theorical basis and data accumulation for the popularization and application of graphene in the field of metal material anti-corrosion.