In Situ Investigation of the Early-Stage Growth of Nanoporous Alumina

Abstract

We report the successful use of in situ grazing incidence small-angle X-ray scattering to follow the anodization of aluminum. A dedicated electrochemical cell was designed and developed for this purpose with low X-ray absorption, with the possibility to access all azimuthal angles (360°) and to remotely control the temperature of the electrolyte. Three well-known fabrication techniques of nanoporous alumina, i.e., single, double, and pretextured, were investigated. The differences in the evolution of the scattering images are described and explained. From these measurements, we could determine at which moment the pores start growing even for very short anodization times. Furthermore, we could follow the thickness of the alumina layer as a function of the anodization time by monitoring the period of the Kiessig fringes. This work is aimed at helping to understand the different steps taking place during the anodization of aluminum at the very early stages of nanoporous alumina formation.

In Situ and Operando X-ray Scattering Methods in Electrochemistry and Electrocatalysis

“…However, most research in this area focused on the self-organized growth of oxides with well-defined ordered arrays of cylindrical pores, especially the growth of porous anodic aluminum oxides . Various groups investigated the structural evolution of the pores during anodic aluminum oxidation by in situ SAXS, , GISAXS, and grazing incidence transmission small-angle X-ray scattering (GTSAXS), , coming to similar conclusions. SAXS measurements can only provide data on the in-plane ordering.…”

Overview of Engineering Carbon Nanomaterials Such As Carbon Nanotubes (CNTs), Carbon Nanofibers (CNFs), Graphene and Nanodiamonds and Other Carbon Allotropes inside Porous Anodic Alumina (PAA) Templates

“…Consequently, much effort must be devoted to obtainin better understanding of the anodization process and the influence of the PAA features the synthesis of nanomaterials within the nanopores. In this direction, many works p forming in-situ time-resolved X-ray scattering observations have been carried out to sh light on the development of the self-ordering pores process [45][46][47][48]. Besides, theoret models are required to precisely establish a theoretical linking between the long-ran Very interesting review articles were published recently that provide an extensive description of the signs of progress made on the PAA fabrication [38,39], characterization [40], formation mechanisms [41,42] and applications [43,44].…”

Evolution of Pore Ordering during Anodizing of Aluminum Single Crystals:In SituSmall-Angle X-ray Scattering Study

“…Later, in 2 M Na 2 SO 4 electrolyte, a linear increase in oxide film thickness with anodizing voltage has been found by X-ray reflectivity measurements . Recently, in situ grazing-incidence small-angle X-ray scattering (GISAXS) and grazing-incidence transmission small-angle X-ray scattering (GTSAXS) have been applied for observation of AAO pores growth and in-plane positional ordering on polycrystalline foils and single-crystal substrates. − …”