Hydrothermal synthesis and tribological properties of MoSe2 nanoflowers

Molybdenum selenide (MoSe₂) nanoflowers have been favourably synthesised by a mild hydrothermal route using sodium molybdate and selenium powder at low temperatures. The gained crystallographic products were analysed by powder X-ray powder diffraction (XRD), energy-dispersive spectroscopy, scanning electron microscopy (SEM) and high-resolution transmission electron microscopy. The XRD pattern of the product can be easily indexed to hexagonal MoSe₂. SEM and transmission electron microscopy graphics of the products reveal that the MoSe₂ nanoflowers with diameters of about 100 nm consist of nanosheets. The tribological behaviours of MoSe₂ as oil additives were evaluated on a ball-on-disc tribometer. Under the given experimental conditions, the oil containing MoSe₂ gave lower friction coefficients than that of the base oil. A smooth tribofilm formed on worn surfaces is believed to be responsible for the good lubricating effects of MoSe₂ as additives.