Friction behavior of in situ hydrothermal fabrication of sulfide film on copper

Cu2S films on the copper substrate are successfully prepared through the in-situ hydrothermal reaction between sulfur powder and copper foil. The morphological and chemical structures of films were investigated by using scanning electron microscopy and X-ray photoelectron spectroscopy. The friction-reducing performance of Cu2S film obtained was evaluated in dry sliding contact with steel ball. It is observed that as-obtained Cu2S films have the water contact angle as high as 140° without any chemical modification, possessing low friction with extremely long duration.