The keys to avoid undesired structural defects in nanotubular TiO2 films prepared by electrochemical anodization

Broens, Martín I.; Cervantes, Wilkendry Ramos; Jerez, Diego Oyarzún; Teijelo, M. López; Pérez, Omar E. Linarez

doi:10.1016/j.ceramint.2020.02.145

Cited by 16 publications

(4 citation statements)

References 65 publications

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“…However, the higher percentage of NH4F reduced the length, which can be caused by the drastic chemical dissolution due to the increased number of fluoride ions on the surface of TNTAs. Whereas the diameter of the TNTAs exhibited a marginal increase with the increase in NH4F content [25]. During the anodization process, the growth of oxide thickness is due to the ion migration across the anodic film.…”

Section: Parametric Studymentioning

confidence: 95%

Influence of Anodizing Parameters on the Morphological Characteristics of TNTAs

Aamina,

Hossen,

Abd Aziz

2023

Constr.

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TiO2 nanotubes arrays (TNTAs) were synthesized using the anodization method in ethylene glycol (EG)-based electrolyte with different percentages of ammonium fluoride (0.3, 0.4, and 0.5 wt.%) and water content (2.5, 5, and 7.5% vol%). All the samples were ultrasonically cleaned in acetone, ethanol, and deionized water, then dried in air and kept in an etching solution for a while before anodization. The two-step anodization was carried out, followed by thermal treatment at 450°C for the crystallization. The nanotube samples were characterized using FE-SEM analysis. The FE-SEM results showed that the largest tube diameter was 87.74±1.89 nm of the TNTAs prepared in the EG electrolyte with a composition of 7.5% water content and 0.5% ammonium fluoride. The longest tube length analyzed was around 5.3 µm of the TNTAs prepared in the ethylene glycol electrolyte with the composition of 2.5% water content and 0.4% ammonium fluoride percentage, exhibiting a highly ordered, compact honeycomb structure and thick single-walled structure.

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Section: Parametric Studymentioning

confidence: 95%

Influence of Anodizing Parameters on the Morphological Characteristics of TNTAs

Aamina,

Hossen,

Abd Aziz

2023

Constr.

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“…TiO 2 nanotubes prepared through electrochemical anodization have found wide applications in catalyst carriers, supercapacitors, biomedicine, and other cutting-edge fields. − However, the formation mechanism of anodic TiO 2 nanotubes remains highly controversial. − The classical field-assisted dissolution theory evolved from porous anodic alumina is still dominant. According to the field-assisted dissolution theory, the dissolution reaction of fluoride ions on titanium oxide is primarily responsible for pore formation in nanotubes. − In recent years, new theories such as the viscous flow model, electric field equilibrium model, and oxygen bubble model have emerged, challenging the classical field-assisted dissolution theory. − Traditional field-assisted dissolution theory fails to explain the three phases of the current–time curve or establish a relationship between the nanotube growth rate and the dissolution rate with respect to anodizing current. − Despite emphasizing a balance between oxide growth and dissolution, few studies have reported on the growth rate and dissolution rate of TiO 2 nanotubes or examined their relationship with fluoride ion concentration. − …”

Section: Introductionmentioning

confidence: 99%

Relationship between the Growth Rate of Nanotubes and the Current–Time Curve of the Anodizing Process

Li,

Han,

Qin

et al. 2024

J. Phys. Chem. C

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The growth mechanism of anodic TiO 2 nanotubes remains unclear. In order to investigate the factors affecting nanotube growth, the growth rate of the nanotubes is analyzed in this paper. TiO 2 nanotubes are successfully prepared in three kinds of electrolytes with equal concentrations of fluoride ions. However, the three groups of nanotubes show significant differences in growth rates (max 207.0 nm/min, min 36.6 nm/min), and the nanotube diameter does not depend solely on the same anodizing voltage, which is contradictory to the field-assisted dissolution reaction involving fluoride ions. The amount of charge accumulated during the growth of the three groups of nanotubes is positively correlated with nanotube length. The interesting results indicate that there is no field-assisted dissolution equilibrium during nanotube growth in fluoride electrolytes, while anodizing current plays a significant role in influencing nanotube growth. Article pubs.acs.org/JPCC

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“…[7][8][9][10][11] However, the formation mechanism of the porous structure and nanotube structure of this kind of porous anodic oxide (PAO) is very controversial. 1,[12][13][14][15][16][17][18] Both formation mechanisms of PAA and anodic TiO 2 nanotubes include the eld-assisted dissolution (FAD), dissolution equilibrium, and eld-assisted ejection (FAE) theories and eld-assisted ow (FAF) model. 1,[19][20][21][22][23][24] There are currently two opposite models of pore formation in these PAOs.…”

Section: Introductionmentioning

confidence: 99%