Theoretical Study of Superlow Friction Between Two Single-Side Hydrogenated Graphene Sheets

First-principles calculations within density functional theory were performed to predict the friction properties between two single-side hydrogenated graphene sheets at the atomic scale. In this study, the coefficients of the friction along two sliding paths were calculated under normal loads ranging from 1 to 9?nN. The calculated results show a general increase of the coefficient of friction with increasing normal load, and the coefficients of friction for this system exhibit an isotropic feature. Coefficients of friction in the range of 0.01?C0.05 were predicted. Compared with clean graphene, the coefficients of friction decreased greatly due to electrons accumulating between the carbon and attached hydrogen atoms, leading to a significant decrease in the potential energy of the single-side hydrogenated graphene. This study suggests that atomic-scale friction may be controlled by adjusting the electronic structure.