Sonochemical preparation and characterization of MoO3 and MoS2 nanoparticles

The effect of ultrasound irradiation on MoO
3
and MoS
2
nanoparticles is investigated. Under ultrasonic irradiation, spherical-like MoO
3
nanoparticles are obtained, while bulk-like MoO
3
nanoparticles were prepared without ultrasonic irradiation. The changes in the physicochemical properties of MoO
3
are investigated by X-ray power diffraction (XRD), field emission scanning electron microscopy (FE-SEM) and ultraviolet and visible spectroscopy (UV-vis). Then MoS
2
nanoparticles are synthesized by the reaction of sulfur powder (S) and ultrasonically prepared spherical-like MoO
3
nanoparticles in a hydrogen atmosphere at a heating temperature of 620°C. Tribological experiments emphasize the important role played by these MoS
2
nanoparticles in providing excellent lubricating performance.