TiO2 nanotube arrays: hydrothermal fabrication and photocatalytic activities

Titanium dioxide nanotube arrays (TiO2 NTAs) with rutile phase have been fabricated successfully via a two-step hydrothermal method. TiO2 nanorod arrays (TiO2 NRAs) are first hydrothermally grown on FTO substrate. Then the TiO2 NTAs can be obtained by controlling the HCl concentration of the hydrothermal etching process. The TiO2 NTAs have been characterized by X-ray diffractometer, scanning electron microscope, transmission electron microscopy, X-ray photoelectron spectroscopy, and ultraviolet–visible spectroscope. Evolution of TiO2 nanoarrays are accompanied by enhanced of the surface area and optical properties. Compared with TiO2 NRAs, the prepared TiO2 NTAs is more efficient in the photodegradation of methyl orange. These results reveal that the hydrothermal chemical etching provide a flexible and straightforward route for design and preparation of TiO2 NTAs, promising for new opportunities in photocatalysts and other fields.