Self-Organized Porous Titanium Oxide Prepared in H[sub 2]SO[sub 4]/HF Electrolytes

Beránek, Radim; Hildebrand, H.; Schmuki, Patrik

doi:10.1149/1.1545192

Cited by 560 publications

(421 citation statements)

References 18 publications

Supporting

Mentioning

393

Contrasting

Unclassified

Order By: Relevance

“…Samples obtained under 30 V exhibited more homogeneous morphologies and exhibited larger nanotube diameters than the samples obtained under 25 V. A similar behavior was observed by Zhao et al, which synthesized TiO 2 -NT during 30 minutes using HF solutions as electrolyte. 29 Similarly to the behavior observed in the present work, the authors have concluded that the potential increase from 20 to 30 V led to an increase in the pore diameter of the TiO 2 -NT.…”

Section: Applied Potential Effectsupporting

confidence: 87%

“…These results are in accordance to Beranek and Zhao , who observed and associated this phenomenon to the solubility of the titanium oxide in fluoride solutions. 28,29 During anodization, the pores on the titanium oxide film tend to grow randomly, as the current density varies with time and, during the pore growing process, the current density decreases and reaches a stable value, for which highly ordered and aligned arrays of titanium oxide nanotubes have been formed. 28,29 In the samples A 1 , A 2 , A 3 , A 4 , A 5 , A 7 , A 9 , A 11 , A 12 , A 13 , A 14 , A 15 , A 16 , A 17 and A 18 were not possible to establish a state of equilibrium between the change in current density and time.…”

Section: Current Density Vs Timementioning

confidence: 99%

See 1 more Smart Citation

Titanium Oxide Nanotubes: Synthesis of Anatase Phase, Characterization and Photocatalytic Application

Filho

Rocco

2013

Revista Virtual De Química

View full text Add to dashboard Cite

Resumo:No presente trabalho, os nanotubos de óxido de titânio foram preparados pelo método de anodização. Neste processo uma chapa do metal titânio foi utilizada como eletrodo de trabalho, sendo o substrato para o crescimento de nanotubos. Uma lâmina de platina foi utilizada como contra-eletrodo. Os nanotubos de óxido de titânio foram sintetizados sob diferentes potenciais (20, 25 e 30 V), e como eletrólito foram usadas soluções aquosas de NaF com concentrações de 0,018 e 0,036 M. As amostras obtidas foram caracterizadas por microscopia eletrônica de varredura, espectroscopia Raman e difração de raios-X, antes e após o processo de recozimento. Todas as amostras após o tratamento térmico exibiram na sua estrutura cristalina exclusivamente a fase de anatásio, com formação bem definida de nanotubos. Foi possível também demonstrar a dinâmica de crescimento dos nanotubos de óxido de titânio, durante o processo de anodização das amostras. A atividade fotocatalítica dos nanotubos de óxido de titânio foi avaliada utilizando-se uma solução aquosa de clorofórmio, tendo sido observada fotodegradação de 51,58%.Palavras-chave: Nanotubos; óxido de titânio; fotocatálise. AbstractsIn the present work, titanium oxide nanotubes were prepared by potentiostatic anodization. A titanium sheet was used as working electrode, serving as substrate for the nanotubes growth. Titanium oxide nanotubes were synthesized under different anodization potentials (20, 25 and 30 V) in 0.18 and 0.36 M NaF aqueous solutions. The samples were characterized by scanning electron microscopy, Raman spectroscopy and X-ray diffraction, before and after a thermal treatment. All samples exhibited only the anatase phase after thermal treatment, for which the formation of well-defined nanotubes was observed. The dynamic growth of titanium oxide nanotubes during the anodization process was confirmed experimentally. The photocatalytic activity of the titanium oxide nanotubes was evaluated for chloroform oxidation, exhibiting photodegradation of 51.58%.

show abstract

Section: Applied Potential Effectsupporting

confidence: 87%

Section: Current Density Vs Timementioning

confidence: 99%

Titanium Oxide Nanotubes: Synthesis of Anatase Phase, Characterization and Photocatalytic Application

Filho

Rocco

2013

Revista Virtual De Química

View full text Add to dashboard Cite

show abstract

“…The nanotube diameter and length can be controlled by the applied potential, the anodization time and the electrolyte used for anodization [17][18][19]. Thus, the first generation of TiO 2 nanotubes produced in HF-containing electrolytes did not exceed a length of approximately 500 -600 nm due to a fast dissolution of TiO 2 by HF [20]. Later on, other electrolytes, i.e.…”

Section: Introductionmentioning

confidence: 99%

Self-organized Anodic TiO2 Nanotube Layers: Influence of the Ti substrate on Nanotube Growth and Dimensions

Sopha

Jäger

Knotek

et al. 2016

Electrochimica Acta

View full text Add to dashboard Cite

In this contribution, various Ti thin substrates were explored and compared for the anodic growth of self-organized TiO 2 nanotube layers for the first time. In order to evaluate differences in the electrochemical anodization characteristics and the tube dimensions, five different Ti substrates from four established suppliers were anodized in the widely used ethylene glycol electrolytes containing 88 mM NH 4 F and 1,5 vol.% water. Two anodizations were carried out to elucidate an influence of the pre-anodized substrates used for the second anodization. By thorough evaluation of the nanotube dimensions, large variations between the dimensions of the nanotubes were found for the different substrates, ranging from ~32 µm to ~50 µm for the nanotube length and from ~109 nm to ~127 nm for the nanotube diameter after the second anodization. Upon AFM measurements, Goodfellow Ti substrates (99.99 % purity), yielded the smoothest surface and the highest degree of ordering from all substrates.Moreover, considerably different consumption of Ti substrates via anodization was revealed by profilometric measurements between the original non-anodized part of the Ti substrates, and the anodized part after the removal of the nanotube layer. Orientation imaging 2 microscopy revealed considerable differences in the size and orientation of the substrate grains.

show abstract

“…Nevertheless, this first generation of nanotubes (including later works by Grimes [38] or Beranek [39]) used acidic, 2 aqueous electrolytes, and led to tubes that showed considerable inhomogeneity in ordering, rough walls, and a tube length limited to < 1 μm.…”

mentioning

confidence: 99%

Anodic TiO2 nanotube layers: Why does self-organized growth occur—A mini review

Zhou

Nguyen

Özkan

et al. 2014

Electrochemistry Communications

169

138

View full text Add to dashboard Cite

The present review gives an overview of the highlights of more than 10 years of research on synthesis and applications of ordered oxide structures (nanotube layers, hexagonal pore arrangements) that are formed by self-organizing anodization of metals. In particular we address the questions after the critical factors that lead to the spectacular self-ordering during the growth of anodic oxides that finally yield morphologies such as highly ordered TiO 2 nanotube arrays and similar structures. Why are tubes and pores formed -what are the key parameters controlling these processes?Link to the published article: http://dx.doi.org/10.1016/j.elecom.2014.06.021 1 Over the past decade, the formation and application of anodic, self-organized TiO 2 nanotube arrays grown from a Ti metal (as illustrated in Fig.1) and similar oxide structures have attracted wide scientific and technological interest [1][2][3][4][5][6][7]. Self-organization during anodization has been observed already more than 70 years ago for aluminum that, when anodized in acidic electrolytes, forms hexagonally ordered porous structures [8] -such ordering can peak in a virtually perfect arrangement, as demonstrated by Masuda et al. in 1995 [9], by a meticulous optimization of the electrochemical growth conditions. These alumina structures since then have been widely used for templating (i.e., to fill the pores by a secondary material to form nanorods or nanowires, in combination with stripping the template or not), as well as for numerous other applications -excellent overviews on growth and applications of porous alumina are available; see e.g. refs. [2][3][4]10,11].In the past few years, however, research activities on ordered TiO 2 nanotube layers have in numbers of paper-output surpassed porous alumina; in the past decade, more than three thousand papers have been published dedicated to anodic TiO 2 nanotubes [1,[5][6][7]. The main reason for this enormous interest is the anticipated impact of such nanotube layers in functional applications of titanium dioxide; such as dye sensitized solar cells [12][13][14][15], photocatalysis [16,17] (including water splitting for the generation of hydrogen, pollution degradation, or the reduction of CO 2 ), biomedicine [18][19][20] (biomedical coatings of implants, drug delivery systems), ion-insertion batteries, electrochromics, etc. [21][22][23][24] These applications are, to a large extent, based on a number of almost unique features of TiO 2 [1,[25][26][27][28]: it is a semiconductor of a band-gap of 3.0 eV (rutile) -3.2 eV (anatase), with a considerably large electron diffusion length (mainly anatase), relative band-edge positions suitable to trigger a wide range of photocatalytic reactions; the material is highly biocompatible, and shows considerably good ion intercalation properties. Many of these features can be exploited in a nanotubular form even more beneficially than in powder assemblies (e.g. directional charge transport, orthogonal carrier separation, optimized and directional diffusion profile...

show abstract

Self-Organized Porous Titanium Oxide Prepared in H[sub 2]SO[sub 4]/HF Electrolytes

Cited by 560 publications

References 18 publications

Titanium Oxide Nanotubes: Synthesis of Anatase Phase, Characterization and Photocatalytic Application

Titanium Oxide Nanotubes: Synthesis of Anatase Phase, Characterization and Photocatalytic Application

Self-organized Anodic TiO2 Nanotube Layers: Influence of the Ti substrate on Nanotube Growth and Dimensions

Anodic TiO2 nanotube layers: Why does self-organized growth occur—A mini review

Contact Info

Product

Resources

About