▎ 摘　　要

This study uses the molecular dynamics approach to design graphene nanoparticles from the graphene sheets seeded randomly and investigates their lubricity. These nanoparticles are found to provide stable lubrication at extremely high pressure and temperature of up to 15 GPa and 2000 K, respectively. From the influences of both nanoparticle and graphene, the friction between the diamond slab and the nanoparticles shows ultralow values of the friction coefficient of 0.0034-0.0162 under 1-15 GPa and 300 K and 0.0065-0.0338 under 300-2000 K and 1 or 10 GPa. Providing stable lubrication and ultralow friction under these conditions is the large advantage of graphene nanoparticles.