Synthesis of Ni/Co/Ni−G Composite Coatings and Analysis of Their Corrosion Resistance Properties to Q235 Carbon Steel.

In this work, nickel‐modified graphene nanosheets (Ni−G) were prepared by hydrothermal method for the first time. The microscopic morphological analysis showed that the nickel nanoparticles were successfully reductively deposited on the surface of Ni−G with uniform distribution. Ni−G can be uniformly and stably dispersed in the electrodeposition solution. Then Ni/Co/Ni−G composite coating was prepared by pulsed current co‐deposition method to provide corrosion resistance protection for Q235 carbon steel. The microstructure and morphology analysis of the composite coating shows that Ni−G were homogeneously incorporated in the coating and the composite coatings were uniform, dense and crack‐free. The hardness test results showed that the doping of Ni−G improved the hardness of the composite coating. The influence of the added amount of Ni−G in the electrodeposition solution on the anti‐corrosion performance of the composite coating was investigated. The electrochemical results illustrated that the composite coating prepared by adding 20 mL Ni−G dispersion achieved 98.04 % protection efficiency (η ${\eta }$ EIS) against carbon steel substrate in 3.5 wt.% NaCl solution, the Ni/Co/Ni−G20 composite coating has the best corrosion resistance. [ABSTRACT FROM AUTHOR]