In situ fabrication of alumina nanotube array and photoluminescence

Abstract

Aluminum foil was anodized in aged electrolyte under high voltage. The morphology observation shows that the alumina film has a three-layer structure from bottom to top and the middle layer shows large quantities of individual alumina nanotubes. Their formation mechanism is discussed in detail. Under ultraviolet excitation, the alumina film exhibits an emission centered at ϳ400 nm. Based on annealing behavior of the emission band and electron paramagnetic resonance result, the origin of the emission is considered to be due to optical transition in single ionized oxygen vacancy ͑F + center͒ in the alumina. The experimental results can be expected to have favorable applications in optoelectronics and biotechnology.

Improved performance in dye-sensitized solar cells by rationally tailoring anodic TiO2 nanotube length

“…The growing rate of the TiO 2 nanotubes is calculated as high as 28 lm/h, which is much higher than what was reported previously [35,36] (15 lm/h). In fact, this phenomenon was also observed in the growth of anodic aluminum oxide (AAO) nanostructures by using used or aged solutions [37][38][39]. The AAO growth rate increased rapidly as compared to that by using the fresh electrolyte.…”

Highly Ordered Anodic Porous Alumina Formation by Self‐Organized Anodizing

“…It is widely recognized that porous alumina exhibits a blue photoluminescence (PL) band [319][320][321][322][323][324][325][326], with the emission bands being attributed to optical transition in the singly ionized oxygen vacancies (F þ centers) or to electrolyte impurities embedded in the porous alumina membranes. The oxygen vacancies are produced in the alumina matrix as a result of enhanced consumption of OH À in the electrolyte near the anode occurring during the anodization of aluminum [326]. In contrast, the influence of various additives, such as sulfosalicylic acid, Eu 3þ and Tb 3þ ions, on the photoluminescence spectra were investigated [322,[327][328][329].…”

Investigation of intrinsic mechanisms of aluminium anodization processes by analyzing the current density

“…fabricating AAO tubes with controllable diverse microstructural morphologies (e.g., fusiform or other shapes) by accurately designing and controlling the i a pulse or U a pulse, which may have potential uses in many fields, such as drug carrier, slow release technique, sensors, etc. [55][56][57][58][59]…”