In order to improve the lubrication performance of graphene lubricating oil

the friction and wear properties of graphene-based carbon quantum dot composites as lubricant additives were studied. Carbon quantum dots (CQDs) were fabricated by pyrolysis with citric acid as the precursor

and CQDs/graphene composites were fabricated by hydrothermal synthesis

the dispersion stability of additives was studied by static precipitation method

the friction and wear tests were carried out by Rtec friction and wear testing machine

the tribological properties of the synergy between CQDs and graphene were explored

and the composites and wear marks were characterized and analyzed. Comparing with CQDs and graphene

CQDs/graphene showed better dispersion. CQDs/graphene lubricating oil has the most significant anti-friction and anti-wear effect

and the lubrication effect is the best when the mass ratio of CQDs/graphene is 4∶1. At 40 N

the average coefficient of friction is reduced by 57.9% comparing with graphene lubricant. CQDs/graphene lubricants produce a range of carbon oxides and other tribochemical products in friction that form a protective film. It can be seen that the introduction of CQDs can improve the tribological properties of graphene lubricating oils.