Dynamic electron transfer for reducing nanofriction of graphene at electrified interfaces

Nanofriction properties of graphene at electrified interfaces are important for the application of graphene as a solid lubricant in graphene-based electric-carrying interfaces. The nanofriction experiments based on conductive atomic force microscopy show that dynamic electron transfer determines nanofriction of graphene at the electrified interfaces. Nanofriction at highly conductive interfaces remain constant because the fast electron transfer decreases the electrical potential difference. However, nanofriction at low conductive interfaces increases because electron blocking increases the electrical potential difference. The nanofriction of graphene correlated negatively with loads at low conductive interfaces because high loads decrease the contact resistance to release blocked electrons. Furthermore, large graphene possesses higher nanofriction than small graphene. Scanning Kelvin force microscopy measurements show that the larger electron capacity of large graphene can maintain the electrical potential difference at interfaces. These studies provide beneficial guidelines for the applications of graphene as a solid lubricant at electrified interfaces. © 2020