The effect of graphene synthesis duration and copper textures on corrosive behavior and surface wettability.

Research into the corrosion behavior of a copper substrate with a graphene coating synthesized using the CVD method has been performed. The influence of various copper substrates with varying substrate thickness, time of high-temperature annealing and duration of graphene synthesis was investigated. Different synthesis durations allowed studying the corrosive current on the copper surface: (a) not fully covered with graphene, (b) completely covered with single-layer graphene and (c) when there are areas with several graphene layers on the surface. Electrochemical corrosion in saline solution was realized at high and low potentials of the working electrode, which enabled assessment of the limiting factors of corrosion. At a low potential, the mass of corrosion products decreased by an order of magnitude. A hypothesis explaining the formation of deep corrosion pits of rectangular shape was proposed. The energy-dispersive X-ray analysis (EDAX) demonstrated that with a high potential of the working electrode, an essentially heterogeneous distribution of carbon and copper is realized (compared with a lower potential of the electrode). With the duration of graphene synthesis from 0 to 10 min, the corrosion current decreases almost 10 times. With a further increase in the duration of synthesis, the corrosion current drops slightly. The performed MD simulation on wettability corresponds to the experimental data. The obtained results may be useful for the development of the technology of defect-free graphene-based sensors that are less sensitive to corrosion. [ABSTRACT FROM AUTHOR]