Highly ordered self-organized TiO2 nanotube arrays prepared by a multi-step anodic oxidation process

Abstract

Highly ordered TiO2 nanotube arrays were prepared using a self-templating multi-step anodic oxidation process in a fluoride-containing electrolyte. The microstructures, chemical compositions, and phases of the self-organized TiO2 nanotube arrays were analyzed by FESEM, XPS, and XRD, respectively. Hexagonal packing density in TiO2 nanotube arrays significantly improved after the the multi-step anodic oxidation. The area densities of the hexagonal TiO2 nanotube arrays increased approximately 3 times from the first to second step in the anodic oxidation steps process (4.9 µm − 2 to 16.4 µm − 2 ), but there was no difference between the second and third step (16.4 µm − 2 to 16.0 µm − 2). The as-anodized TiO2 nanotube array had an amorphous structure and it transformed to an anatase phase during the annealing process at 450°C for 1 h. The as-anodized TiO2 nanotube arrays adsorbed the fluoride, hydrocarbon groups (CH), hydroxyl groups (OH, C-OH), and carboxyl groups (O = C-OH) on their surfaces.

Effects of calcium and phosphorus incorporation on the properties and bioactivity of TiO2 nanotubes

“…The peak separation of 5.7 eV between the Ti2p 1/2 and Ti2p 3/2 signals corresponds to the values reported in literature. 54 The O1s spectrum of the TiO 2 layer is observed in Figure 3c, where the main peak can be attributed to Ti-O groups at BE ¼ 530.9 eV. The fitting of O1s signal resulted in a second peak located at a BE of 531.6 eV.…”

A highly sensitive BTX sensor based on electrochemically derived wall connected TiO2 nanotubes

“…The XPS survey (Fig. 6) revealed the existence C (1s), Ti (2p) and O (1s) peaks at ~284 eV, ~460 eV and ~530eV, respectively, within the range of 0-700 eV [26,27]. In case of S3, S4, S5 and S6, an additional peak at lower energy (~37.5 eV) side is evident which can be identified as Ti (3p) peak [26].…”

“…8). The first one is related to Ti-O bond from lattice; whereas, the second one is due to adsorbed -OH group [27].…”

Peculiar Porous Aluminum Oxide Films Produced via Electrochemical Anodizing in Malonic Acid Solution with Arsenazo-I Additive

“…The ratio of simultaneously occurring self-organized processes of metal oxidation with the formation of oxide and dissolution plays an important role in the formation of porous and tubular anodic oxides of valve metals. Different kinds of metal dissolution during anodic oxidation of aluminum and other valve metals lead to the formation of oxide films with different morphologies: barrier layers, quasi-regular porous layers, high degree self-ordering porous layers as well as tubular and nanocomposite structures [ 6 , 12 , 13 , 14 , 15 , 16 , 17 , 18 , 19 , 20 , 21 , 22 , 23 , 24 , 25 , 26 , 27 , 28 , 29 , 30 , 31 , 32 , 33 , 34 ]. The anodizing electrolyte is, aside from other process parameters, the main factor that determines this morphology.…”