Anodic Growth of Large-Diameter Multipodal TiO₂ Nanotubes

Abstract

We report on the formation of a new class of nanostructures, namely, multipodal hollow titania nanotubes possessing two or more legs, achieved during the electrochemical anodization of titanium in diethylene glycol (DEG)-based electrolytes. The unique multipodal porous structure is expected to extend and enhance the applications of TiO(2) nanotube arrays. Multipodal nanotubes form by a process we term "nanotube combination", which only occurs in viscous electrolytes at high anodization potentials in the presence of a low concentration of fluoride-bearing species. The mechanism of formation of multipodal nanotubes is considered, and the tube length at which nanotube combination occurs is predicted theoretically using a simplified analytical model. The results suggest that capillary forces strong enough to bend the TiO(2) nanotubes by tens of degrees are generated during the imbibition of electrolyte into and out of the intertubular spaces between adjacent tapered nanotubes.

Observation of crystalline changes of titanium dioxide during lithium insertion by visible spectrum analysis

“…This is an apt interpretation of the previous experimental observation of the longitudinally multipodal structure of TiO 2 via anodic growth as well. 38 The structure is numerically represented by a slit; therefore, we calculated fingerprinted reflectance spectra of the nano-slit structure (Fig. 4).…”

α-Fe2O3/Ti–Nb–Zr–O composite photoanode for enhanced photoelectrochemical water splitting

“…In order to improve the catalytic activity of TiO 2 , many elements (Fe, Mo, Cr, B, C, N, S and F) have been used to dope TiO 2 [6][7][8][9][10][11][12]. Recently, one dimensional nanotubular structures have aroused great interests mainly due to their high surface area and easily functionalized architecture with vectorial electro percolation pathways to reduce the recombination of electron [13]. Electrochemical anodization was an effective method to fabricate doped TiO 2 nanotubes.…”

Improved photo-catalytic activity of single-crystalline TiO2 nanowires surrounded by Pt cube nanoparticles

“…Recently, considerable effort has been focused on exploring diverse synthetic methods ranging from vapor-phase techniques to solution-growth processes for the synthesis of 1-D nanostructure TiO 2 [6][7][8][9]. In particular, in the case of nanobelts or nanotubes, it is well known that various types of TiO 2 nanostructures can be synthesized through strong acid treatment under hydrothermal or non-hydrothermal conditions [10][11][12][13][14]. Among the one-dimensional nanostructures, the nanowire electrode shows particular properties such as rapid electron collection of carriers and charge transport assisted by its one-dimensional structure [15][16][17][18][19].…”