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Voids in walls of mesoporous TiO2 anatase nanotubes by controlled formation and annihilation of protonated titanium vacancies

Voids in walls of mesoporous TiO2 anatase nanotubes by controlled formation and annihilation of protonated titanium vacancies

Category
Journal publication
Abstract
Amorphous TiO2 nanotubes (TNTs) grown anodically on Ti metal in aqueous electrolytes show a crystallization behaviour strongly dependent on the atmosphere used during annealing at high temperature. In wet oxidizing conditions, the amorphous TNTs walls transform into relatively large and well crystallized anatase-like domains permeated by prismatic voids. On the other hand, crystallization of the amorphous nanotubes under dry reducing conditions induces nanocrystalline aggregates that do not show prismatic voids and exhibit different electronic properties. Supported by density functional theory calculations, it is argued that the formation or absence of voids can be understood in terms of formation and condensation of protonated titanium vacancies. Tunable morphology through defect chemical engineering as such, enables TNTs with increased surface area and catalytic activity, which find potential application in supercapacitors, sensors, photocatalysis, photoelectrochemistry, and dye-sensitized solar cells.
Client
  • Universitetet i Oslo / NOTUR NN4604K
  • Norges forskningsråd / 275058
Language
English
Author(s)
  • Getz Marit Norderhaug
  • Chatzitakis Athanasios Eleftherios
  • Liu Xin
  • Almeida Carvalho Patricia
  • Bjørheim Tor Svendsen
  • Norby Truls Eivind
Affiliation
  • University of Oslo
  • SINTEF Industry / Sustainable Energy Technology
  • University of Oslo
  • University of Oslo
Year
2020
Published in
Materials Chemistry and Physics
ISSN
0254-0584
Volume
239
Page(s)
121953