The advent in nanotechnology has provided unprecedented opportunities for photocatalytic application. Highly ordered TiO2 nanotube arrays have some astounding features such as semiconducting and biocompatibility properties coupled with ordered nanotube arrangement, high surface-to-volume ratios and excellent electrons/holes separation properties. These remarkable structure-dependent properties have far reaching application potential in photocatalytic applications such as photoelectrolysis, photocatalysis, photoelectrochemical water splitting, dye-sensitized solar cell (DSC) and biological applications. This review summarizes the photocatalytic mechanism of TiO2 nanotube arrays and their preparation process of electrochemical anodization, illustrates their photocatalytic applications in DSC, photoelectrochemical water splitting and hydrogen sensing.