Laser hydrothermal reductive ablation of titanium monoxide: Hydrated TiO particles with modified Ti/O surface

IR laser- and UV laser-induced ablation of titanium monoxide (TM) in hydrogen (50 Torr) is compared to the same process induced in vacuum and shown to result in deposition of hydrated surface modified nanostructured titanium suboxide films. Complementary analyses of the films deposited in vacuum and in hydrogen by Fourier transform infrared, Raman and X-ray photoelectron spectroscopy, X-ray diffraction and electron microscopy allowed to determine different features of both films and propose a mechanism of surface modification of ejected particles, which involves hydrothermal reduction of TM and subsequent reactions of evolved water. The films exert good adhesion to metal and quartz surfaces and are hydrophobic in spite of having their surface coated with adsorbed water. - Graphical abstract: Laser ablation of titanium monoxide (TiO) in hydrogen involves a sequence of H2 and H2O eliminations and additions and yields hydrated amorphous nanostructured titanium suboxide which is richer in oxygen than TiO. Highlights: ► IR and UV laser ablated particles of titanium monoxide (TiO) undergo amorphization. ► Films deposited in vacuum have TiO stoichiometry and are oxidized in atmosphere. ► Films deposited in hydrogen are hydrated and have more O in topmost layers. ► Films modification in hydrogen is explained by reactions in hydrogen plasma.