Abstract (EN):
Highly ordered TiO2 nanotubes (NTs) were synthesized by the electrochemical anodization of Ti
foils subjected to electropolishing (EP) pre-treatment. We found that the Ti surface roughness
plays an important role in the onset of pore nucleation in enhancing the local focusing effect of
the electrical field. Additionally, EP induces the formation of dimple structures on the metal
surface, which can work as a pre-pattern prior to anodization. These shallow ripples lead to a
preferentially ordered pore nucleation, offering an organizational improvement of the anodic
oxide NTs. We found that, depending on the EP applied potential, the roughness and the spatial
period of the ripple-like structures varies from 8¿2 nm and from 122¿30 nm, respectively. Such
tuning allowed us to focus on the influence of the initial Ti pre-surface topography features on
the NTs¿ length, organization, and hexagonal arrangement quality, as well as diameter and
density. Our results show that an EP under 10 V is the most suitable to obtain a small Ti surface
roughness, the largest NT length (40% enhancement), and the effective improvement of the
ordered hexagonal NTs¿ arrays over larger areas. Furthermore, the NTs¿ dimensions (pore
diameters and density) were also found to depend on the initial Ti surface topography. The use of
optimized EP allows us to obtain highly hexagonal self-ordered samples at a reduced time
and cost.
Idioma:
Inglês
Tipo (Avaliação Docente):
Científica
Notas:
Publicação abrangida pelo Journal Citation Reports 2015
Nº de páginas:
11
Tipo de Licença: