Black phosphorus quantum dots: A new-type of water-based high-efficiency lubricant additive

摘要

Black phosphorus quantum dots(BPQDs),obtained via a typical solution-based top-down method,were used as water-based lubricant additives.BPQDs exhibited remarkable friction reduction and anti-wear properties even at the ultra-low concentration of 0.005 wt%,which reduced the friction coefficient and wear volume of the base liquid by 32.3%and 56.4%,respectively.In addition,the load-supporting capacity of the base liquid increased from 120 N to over 300 N.BPQDs-based additives exhibited a relatively long lifetime at a relatively high load of 80 N.The performance of BPQDs considerably exceeded that of the BP;this may be attributed to their small and uniform particle size,good dispersion stability in water,and high reactivity at the frictional surfaces.The results of the surface wear resistance analysis demonstrated that a robust tribochemical film with a thickness of approximately 90 nm was formed on the rubbing surface lubricated with 0.005 wt%of BPQDs dispersion.Moreover,the film served as a direct evidence of the excellent tribological performance of BPQDs.