One-step hydrothermal synthesis of reduced graphene oxide/zinc sulfide hybrids for enhanced tribological properties of epoxy coatings

Advanced reduced graphene oxide/ZnS (RGO/ZnS) hybrids were synthesized via a facile and effective hydrothermal method to enhance the tribological properties of epoxy coatings. Physical characterization of the hybrids indicated that the as-prepared products had the high chemical purity and that the ZnS nanoparticles combined well with RGO nanosheets. Meanwhile, ZnS nanoparticles were uniformly dispersed on RGO nanosheets with the diameters of several decade nanometers. The tribological properties of ZnS, RGO, and RGO/ZnS with epoxy coating were systematically investigated. By comparing the result of tribological study, it was found that RGO/ZnS hybrids had better lubricating properties with lower coefficient of friction and higher wear resistance than those of ZnS or RGO. In addition, the test results indicated that RGO/ZnS hybrids showed good stability with increased in applied load. These excellent tribological properties of RGO/ZnS hybrids were attributed to the excellent synergistic effects between ZnS nanoparticles and RGO nanosheets and to the transfer film that formed on the steel ball. This work paved a way to expand the potential applications of nanoparticles in the tribological field.