Graphene/H-Bn Nanosheets/Nanospheres Composite Constructed by In-Situ Laser Irradiation with Synergistically Improved Tribological Performance

Graphene/hexagonal boron nitride composites have great application prospects in the field of lubrication due to their unique layered structure and excellent mechanical properties. However, due to their complex synthesis process, easy agglomeration and poor stability, graphene/hexagonal boron nitride composites have not yet been applied in practical applications. Herein, a simple and green in-situ laser irradiation method was proposed to construct laser-induced reduced graphene oxide/hexagonal boron nitride nanosheets/nanospheres composite (L-rGO/h-BN). During the one-step laser irradiation in liquid, graphene oxide (GO) nanosheets were reduced to reduced graphene oxide (rGO) nanosheets. Meanwhile, hexagonal boron nitride (h-BN) nanoflakes were transformed into h-BN nanospheres, and embedded into multilayer grapheme nanosheets. The spherical h-BN nanoparticles as support can maintain the graphene of more stable layered structure, while the insertion of graphene also effectively inhibits the agglomeration of the spherical h-BN nanoparticles. Importantly, such L-rGO/h-BN composite nanoparticles can be well dispersed in the lubricating oil with no significant precipitation for over 30 days and show remarkable tribological performance. This is due to the synergistic lubricant effect of deposition repair effect from rGO nanaosheets reducing wear and micro-bearing effect from h-BN nanospheres reducing friction by changing sliding friction into rolling friction