Hydrothermal synthesis of anatase-type TiO2 films on Ti and Ti–Nb substrates

The hydrothermal synthesis of anatase-type TiO2 films on Ti and Ti–Nb substrates was examined with a focus on crystallinity and surface morphology of the films. The substrates were chemically treated with H2O2/HCl or H2O2/HNO3 solution to prepare amorphous-like TiO2. The hydrothermal treatment of the resultant films was performed in an autoclave with deionized water or NH3 aqueous solution. The synthesized anatase-type TiO2 films showed high crystallinity and rectangular morphology. The (Ti, Nb)O2 film could be obtained by using Ti–Nb alloys as substrates.