scholarly journals Electrochemical Anodization and Characterization of Titanium Oxide Nanotubes for Photo Electrochemical Cells

2021 ◽  
Vol 2070 (1) ◽  
pp. 012073
Author(s):  
C U Bhadra ◽  
D Henry Raja ◽  
D Jonas Davidson
Keyword(s):  
Titanium Oxide ◽  
Oxygen Vacancies ◽  
Ammonium Fluoride ◽  
Band Gap Energy ◽  
Electrochemical Anodization ◽  
Nanotube Arrays ◽  
Photoluminescence Intensity ◽  
Titania Nanotube Arrays ◽  
Titanium Oxide Nanotubes ◽  
Inner Diameter

Abstract Due to its multitude of applications, titanium oxide is one of the most coveted and most sought-after materials. The above experiment demonstrated that TiO2 nanotube arrays might be formed by electrochemical anodization of titanium foil. The 0.25 wt% ammonium fluoride (NH4F) was added to a solution of 99% ethylene glycol. Anodization is carried out at a constant DC voltage of 12V for 1 hour. Then, the annealing process is carried out for 1 hour at 4800C, which is known as an annealing. FE-SEM were utilized to evaluate the surface morphology of the nanotube arrays that were made. At the wavelength of 405 nm, sharply peaked photoluminescence intensity was observed, which corresponded tothe band gap energy (3.2 eV) of the anatase TiO2 phase. Since free excitations appear at 391 and 496 nm, and since oxygen vacancies are developed on the surface of titania nanotube arrays, it is reasonable to conclude that free excitations and oxygen vacancies are the causes of humps at 391 and 496 nm, and that they may also be present at 412 and 450 nm. FESEM results showed uniformly aligned TiO2 nanotube arrays with an inner diameter of 100 nm and a wall thickness of 50 nm

Effect of Fluoride Concentration and Water Content on Morphology of Titania Nanotubes in Ethylene Glycol Solution

2013 ◽  
Vol 829 ◽  
pp. 907-911 ◽  
Author(s):  
Meysam Naghizadeh ◽  
Saber Ghannadi ◽  
Hossein Abdizadeh ◽  
Mohammad Reza Golobostanfard
Keyword(s):  
Ethylene Glycol ◽  
Water Content ◽  
Fluoride Concentration ◽  
Pure Titanium ◽  
Ammonium Fluoride ◽  
Electrochemical Anodization ◽  
Nanotube Arrays ◽  
Geometrical Parameters ◽  
High Concentration ◽  
Inner Diameter

Titanium dioxide (TiO2) nanotube arrays were prepared at room temperature by electrochemical anodization of a pure titanium foil in electrolyte solutions containing ethylene glycol as a solvent and de-ionized water and ammonium fluoride as additives. Since the morphology and size of TiO2 nanotubes play critical roles in determining their performance, the control of geometrical parameters of the nanotube arrays including length and inner diameter are of great importance. The present research demonstrates the significant effects of fluoride concentration and water content in anodizing electrolyte on formation of nanotubes and their dimensions. Scanning electron microscope investigation shows that nanotube arrays are no longer formed in very low or very high concentration of ammonium fluoride. Also, increase in fluoride concentration causes increase in lengths and inner diameters of the nanotubes. Moreover, it is evident that the maximum nanotube growth rate was achieved in medium amount of water. In addition, it is found that the nanotube inner diameter increases by adding more water to the solution.

A flexible lead-free piezoelectric nanogenerator based on vertically aligned BaTiO3 nanotube arrays on a Ti-mesh substrate

RSC Advances ◽  
2016 ◽  
Vol 6 (84) ◽  
pp. 81426-81435 ◽  
Author(s):  
Ermias Libnedengel Tsege ◽  
Gyu Han Kim ◽  
Venkateswarlu Annapureddy ◽  
Beomkeun Kim ◽  
Hyung-Kook Kim ◽  
...  
Keyword(s):  
Low Temperature ◽  
Titanium Oxide ◽  
Hydrothermal Process ◽  
Lead Free ◽  
Nanotube Arrays ◽  
Titanium Oxide Nanotubes ◽  
Vertically Aligned ◽  
Ti Mesh

A novel, flexible lead-free piezoelectric nanogenerator was developed using a uniform BaTiO3 film; synthesized by in situ conversion of titanium oxide nanotubes in a low temperature hydrothermal process.

scholarly journals Fabrication, Modification, and Emerging Applications of TiO2Nanotube Arrays by Electrochemical Synthesis: A Review

2013 ◽  
Vol 2013 ◽  
pp. 1-19 ◽  
Author(s):  
Jian-Ying Huang ◽  
Ke-Qin Zhang ◽  
Yue-Kun Lai
Keyword(s):  
Photocatalytic Performance ◽  
Research Work ◽  
Electrochemical Anodization ◽  
Nanotube Arrays ◽  
Forming Mechanism ◽  
Existing Problems ◽  
Titania Nanotube Arrays ◽  
Ordered Array ◽  
New Research ◽  
Degradation Of Pollutants

Titania nanotube arrays (TNAs) as a hot nanomaterial have a unique highly ordered array structure and good mechanical and chemical stability, as well as excellent anticorrosion, biocompatible, and photocatalytic performance. It has been fabricated by a facile electrochemical anodization in electrolytes containing small amounts of fluoric ions. In combination with our research work, we review the recent progress of the new research achievements of TNAs on the preparation processes, forming mechanism, and modification. In addition, we will review the potential and significant applications in the photocatalytic degradation of pollutants, solar cells, water splitting, and other aspects. Finally, the existing problems and further prospects of this renascent and rapidly developing field are also briefly addressed and discussed.

EFFECT OF VOLTAGE ON TIO2 NANOTUBES FORMATION IN ETHYLENE GLYCOL SOLUTION

2017 ◽  
Vol 79 (5-2) ◽  
Author(s):  
Syahriza Ismail ◽  
Khairil Azwa Khairul ◽  
Nurul Asyikin Ahmad Nor Hisham ◽  
Md Shuhazlly Mamat ◽  
Mohd Asyadi Azam
Keyword(s):  
Heat Treatment ◽  
Ethylene Glycol ◽  
Crystalline Phase ◽  
Tio2 Nanotubes ◽  
Oxygen Vacancies ◽  
Ammonium Fluoride ◽  
Nanotube Arrays ◽  
Anodization Voltage ◽  
Ionic Mobilities ◽  
Glycol Solution

The crystalline phase of the TiO2 nanotubes without further heat treatment were studied. The TiO2 nanotube arrays were produced by anodization of Ti foil at three different voltage; 10, 40, and 60 V in a bath with electrolytes composed of ethylene glycol (EG), ammonium fluoride (NH4F), and hydrogen peroxide (H2O2). The H2O2 is a strong oxidizing agent which was used as oxygen provider to increase the oxidation rate for synthesizing highly ordered and smooth TiO2 nanotubes. Anodization at voltage greater than 10 V leads to the formation of tubular structure where higher anodization voltage (~ 60 V) yield to larger tube diameter (~ 180 nm). Crystallinity of the nanotubes is improved as the voltage was increased. The transformation of amorphous to anatase can be obtained for as anodized TiO2 without any heat treatment. The Raman spectra results show the anodization at 40 V and 60 V gives anatase peak in which confirms the crystalline phase. The stabilization of the crystalline phase is due to the oxygen vacancies and ionic mobilities during the anodization at high voltage. 

Synthesis of Highly Ordered Nanotubular Oxide Layers on Ti-6Al-4V Alloys by Anodization Technique

2011 ◽  
Vol 219-220 ◽  
pp. 1541-1544
Author(s):  
Shi Kai Liu ◽  
Hong Sen Zuo ◽  
Hai Bin Yang ◽  
Wen Jun Zou ◽  
Zheng Xin Li
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Applied Voltage ◽  
Electrochemical Anodization ◽  
Tube Length ◽  
Nanotube Arrays ◽  
Anodization Time ◽  
Tc4 Alloy ◽  
Inner Diameter ◽  
Scanning Electron

Highly ordered nanotube arrays were fabricated via electrochemical anodization of Ti-6Al-4V (TC4) alloy foils in aqueous fluorine containing electrolytes. The formation of ordered nanotubular films was affected by the applied anodization potential and the anodization time. The optimal applied voltage and anodization time were 20V and 1h, respectively, as-prepared anodic nanotubular films were in highly ordered with the average inner diameter of about 120nm, the wall thickness of 17nm and the tube length about 300nm. The tubular nanostructures were examined by field emission scanning electron microscopy. The possible nanotube formation mechanism was also discussed.

Titanium oxide nanotube arrays prepared by anodic oxidation

2001 ◽  
Vol 16 (12) ◽  
pp. 3331-3334 ◽  
Author(s):  
Dawei Gong ◽  
Craig A. Grimes ◽  
Oomman K. Varghese ◽  
Wenchong Hu ◽  
R. S. Singh ◽  
...  
Keyword(s):  
Titanium Oxide ◽  
Anodic Oxidation ◽  
Hydrofluoric Acid ◽  
Layer Structure ◽  
Porous Alumina ◽  
Pure Titanium ◽  
Nanotube Arrays ◽  
Titanium Sheet ◽  
Anodization Time ◽  
Titanium Oxide Nanotubes

Titanium oxide nanotubes were fabricated by anodic oxidation of a pure titanium sheet in an aqueous solution containing 0.5 to 3.5 wt% hydrofluoric acid. These tubes are well aligned and organized into high-density uniform arrays. While the tops of the tubes are open, the bottoms of the tubes are closed, forming a barrier layer structure similar to that of porous alumina. The average tube diameter, ranging in size from 25 to 65 nm, was found to increase with increasing anodizing voltage, while the length of the tube was found independent of anodization time. A possible growth mechanism is presented.

Crystallization and high-temperature structural stability of titanium oxide nanotube arrays

2003 ◽  
Vol 18 (1) ◽  
pp. 156-165 ◽  
Author(s):  
Oomman K. Varghese ◽  
Dawei Gong ◽  
Maggie Paulose ◽  
Craig A. Grimes ◽  
Elizabeth C. Dickey
Keyword(s):  
Heat Treatment ◽  
High Temperature ◽  
Titanium Oxide ◽  
Elevated Temperatures ◽  
Anatase Phase ◽  
Argon Atmosphere ◽  
Nanotube Arrays ◽  
Nanotube Array ◽  
Inner Diameter ◽  
The Stability

The stability of titanium oxide nanotube arrays at elevated temperatures was studied in dry oxygen as well as dry and humid argon environments. The tubes crystallized in the anatase phase at a temperature of about 280 °C irrespective of the ambient. Anatase crystallites formed inside the tube walls and transformed completely to rutile at about 620 °C in dry environments and 570 °C in humid argon. No discernible changes in the dimensions of the tubes were found when the heat treatment was performed in oxygen. However, variations of 10% and 20% in average inner diameter and wall thickness, respectively, were observed when annealing in a dry argon atmosphere at 580 °C for 3 h. Pore shrinkage was even more pronounced in humid argon environments. In all cases the nanotube architecture was found to be stable up to approximately 580 °C, above which oxidation and grain growth in the titanium support disrupted the overlying nanotube array.

scholarly journals An Accurate Growth Mechanism and Photocatalytic Degradation Rhodamine B of Crystalline Nb2O5 Nanotube Arrays

Catalysts ◽  
2020 ◽  
Vol 10 (12) ◽  
pp. 1480
Author(s):  
Wei Guo ◽  
Libin Yang ◽  
Jinghao Lu ◽  
Peng Gao ◽  
Wenjing Li ◽  
...  
Keyword(s):  
Growth Mechanism ◽  
Ion Concentration ◽  
Electrochemical Anodization ◽  
Nanotube Arrays ◽  
Fluoride Ions ◽  
Initial Oxidation ◽  
Increasing Trend ◽  
Key Factor ◽  
Degradation Activity ◽  
Inner Diameter

To effectively improve photocatalytic activity, the morphology and crystallinity of semiconductor photocatalysts must be precisely controlled during the formation process. Self-aligned Nb2O5 nanotube arrays have been successfully fabricated using the electrochemical anodization method. A novel growth mechanism of Nb2O5 nanotubes has been proposed. Starting from the initial oxidation process, the “multi-point” corrosion of fluoride ions is a key factor in the formation of nanotube arrays. The inner diameter and wall thickness of the nanotubes present a gradually increasing trend with increased dissociative fluorine ion concentration and water content in the electrolyte. With dehydroxylation and lattice recombination, the increased crystallinity of Nb2O5 represents a reduction of lattice defects, which effectively facilitates the separation and suppresses the recombination of photo-generated carriers to enhance their catalytic degradation activity.

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