Resistance to Oxidation and Tribological Behavior of MoS2 Nanoparticles in Severe Environmental Conditions

Abstract This study investigates the oxidation resistance and tribological performance of MoS 2 nanoparticles under severe environmental conditions. Friction tests were conducted in dry and strictly controlled environments using a reciprocating pin-on-flat tribometer installed in a controlled environment chamber. This system was connected via a transfer chamber to an XPS spectrometer, enabling post-mortem analysis of the rubbed surfaces without air exposure. The friction tests were performed under pressures ranging from 10 −9 to 200 mbar (simulating ambient air) and at two temperatures (25 and 100 °C). The results show that the nanoparticles maintain excellent tribological performance and good chemical stability from ultrahigh vacuum up to 200 mbar of oxygen at 25 °C, and up to 1 mbar of oxygen at 100 °C. The increase in the friction coefficient observed under certain experimental conditions is attributed to particle oxidation.