Anisotropic oxidation of MoS2 crystallites studied by angle-resolved X-ray photoelectron spectroscopy

The oxidation behavior of the solid lubricant MoS2 was studied using X-ray photoelectron spectroscopy. MoS2-containing slip ring brushes were used to take advantage of anisotropic orientation of the plate-shaped MoS2 crystallites occurring during fabrication of the brushes. Because oxidation occurs preferentially at the edges of the crystallites, greater oxidation fractions are measured when the edges are oriented toward the photoelectron energy analyzer. These results indicate a novel method for separately probing the chemistry on the edge and (lubricious) basal surfaces of MoS2.