Method for preparing single-layer high-activity titanium dioxide thin film

The invention relates to a preparation method for forming single-layer high-activity (001) crystal surface dominating titanium dioxide thin films on different substrates, in particular to the method for growing the (001) crystal surface dominating titanium dioxide thin film consisting of single-layer titanium dioxide particles on a metallic titanium or titanium alloy substrate by a wet chemical process, which solves the problems that (001) dominating titanium dioxide powder difficultly forms a (001) plane totally positioned on a surface and that a compact thin film is difficult to form. In the method, the substrate is placed into a reaction kettle containing the aqueous solution of hydrofluoric acid, and heating treatment is performed at 100 to 200 DEG C for 6 to 24 h to obtain the single-layer (001) crystal surface dominating titanium dioxide thin film. The single-layer (001) crystal surface dominating titanium dioxide thin film consists of anatase and rutile in the radio of 95:5 to 80:20, has the thickness of 10 to 1,000 nm, the controllable (001) crystal surface ratio of 20 to 91 percent and high photoelectrochemical decomposition of water, and is expected to be widely and effectively applied to photocatalytic devices.