In situ synthesis of TiH2 layer on metallic titanium foil through gaseous hydrogen free acid-hydrothermal method

•A dense TiH2 layer is synthesized by a hydrogen free acid-hydrothermal method.•Hydrogen in a TiH2 layer synthesized can release at low temperature.•During the dehydrogenation process, there is no any intermediate phase forming.•We report a method of low-cost, low-risk and convenience toward productive TiH2.

A novel strategy for synthesis of TiH2 layer on surface of metallic titanium by using an acid-hydrothermal method was proposed. During the synthesis process, no any elemental hydrogen was involved. X-ray powder diffraction, energy-dispersive X-ray spectroscopy, X-ray photoelectron spectroscopy and scanning electron microscopy results confirmed that a TiH2 layer of 20 μm thickness on a Ti foil surface can be formed in situ by an interface reaction of metallic titanium with sulfuric acid solution, hydrochloric acid, or phosphoric acid, which is a hydrogen self-storage process. By tuning reaction parameters, for example, concentration of acid, composition and morphology of TiH2-Ti hybrid materials can be adjusted. The TiH2 layer on a metallic titanium surface can be decompounded completely heated below 400 °C. This convenient, safe and low-cost method is a promising gaseous hydrogen free approach for the synthesis of hydride-based hydrogen storage materials.

Graphical abstractThe reaction mechanism for in situ synthesizing TiH2 layer on titanium foil by a gaseous hydrogen free acid-hydrothermal methodology.Figure optionsDownload full-size imageDownload as PowerPoint slide