Facile preparation of flake-like blue TiO2 nanorod arrays for efficient visible light photocatalyst

Different kinds of oriented TiO 2 nanorod arrays have been actively pursuing in recent years, however, these fabrications relied on the substrates, such as fluorine-doped tin oxide glass (FTO), silicon wafer or other semiconductor precursor layer. Herein, a stable Ti 3+ and oxygen vacancies doped blue TiO 2 flakes composed of oriented nanorod arrays were synthesized using a facile hydrothermal treatment in diluted hydrochloric acid solution. Such centimeter-scale flake-like TiO 2 product was obtained without any substrate. Since Ti 3+ self-doped and/or oxygen vacancies TiO 2 could extend the absorption range of TiO 2 to visible light region, the blue TiO 2 sample exhibited excellent photocatalytic activity under visible light irradiation (photocatalytic degradation efficiency can nearly reach up to 100% within 60 min).