Effect of interlayer bonding and stacking structure on the tribological properties of graphene oxide coatings

Graphene oxide (GO) coating is widely used while its lubricating performance depends on the stacking structure and operational environment. Here, GO coatings were fabricated by spraying, spinning, and electrostatic self-assembly using Cu 2+ ion as the coordination. The influence of stacking structure on the tribological properties in humid air, dry nitrogen, and vacuum were evaluated. The results show that Cu 2+ -coordinated self-assembled coatings with strong interlaminar bonding and ordered stacking structure exhibit lower wear under test conditions, especially in a vacuum with a stable friction coefficient of ~0.03, benefit from the increased contact area between GO sheets, reduced stress concentration, inhibited hydrogen bonding between GO and environmental water, and passivates the surface defects of the coating when subjected to shear stress. • Graphene oxide (GO) coatings with different interlayer bonding and stacking structures were fabricated by different processes. • Interlayer bonding and stacking structure are closely related to the tribological properties of GO coatings. • The Cu 2+ -coordinated self-assembled coatings exhibit lower wear under various test conditions owing to strong interlaminar bonding and highly ordered stacking structure. • The coordination of Cu 2+ ions effectively substitution hydrogen bonds between functional groups and water and passivates the surface defects of the coating when subjected to shear stress.