Method for preparing titanium dioxide nanotube array

The invention discloses a method for preparing a titanium dioxide nanotube array, which comprises the following steps: grinding the surface of a titanium sheet by using abrasive paper, polishing by using chemical polishing solution, and drying for later use; preparing electrolyte, wherein a fluoride is used as a solute, water is used as a solvent and an alcohol additive is added; preparing an electrolytic cell having two electrode systems, wherein a titanium sheet is used as an anode, a platinum sheet is used as a counter electrode, and a layer of TiO2 nanotube array can be formed on the surface of the titanium sheet by electrochemical anodic oxidation; subjecting the anodically oxidized titanium sheet to ultrasonic cleaning in acidic solution and drying; and performing anodic oxidation again by using the titanium sheet as the anode, and thus, forming the TiO2 nanotube array with uniform pipe diameter and flat surface on the surface of the titanium sheet. In the method, the problems of non-uniform tube diameter, uneven nantube surface and irregular array of two-step anodic oxidization are solved, and the titanium dioxide nanotube array with more regular shape is formed.