Synthesis of reduced graphene oxide/Cu nanoparticle composites and their tribological properties

Abstract

The reduced graphene oxide/Cu nanoparticle (RGO–Cu NP) composites were synthesized by a facile and effective chemical reduction method. The morphology and structure of the RGO–Cu NP composites were characterized by X-ray diffraction, scanning electron microscopy, and Fourier trans form-infrared spectroscopy. The results indicated that Cu nanoparticles (Cu NPs) were well distributed on RGO nanosheets with an average diameter of 20 nm. The performance of the RGO–Cu NP composites as a lubricating oil additive was investigated by employing a ball–plate tribotester. It showed improved wear resistance and load-carrying capacity over those in the oil with RGO nanosheets. Scanning electron microscopy performed to analyze the wear scar surfaces after friction confirmed that the outstanding lubrication performance of composites could be attributed to their extremely thin laminated structure and the synergistic effect mechanism of RGO–Cu NP composites in base oil.