Study of the highly ordered TiO2 nanotubes physical properties prepared with two-step anodization

Pishkar, Negin; Ghoranneviss, M.; Ghorannevis, Zohreh; Akbari, Hossein

doi:10.1016/j.rinp.2018.02.009

Cited by 35 publications

(24 citation statements)

References 26 publications

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“…Notably, the preferred orientation changed from (101) for TNAs to (004) for N-TNAs. The reason is not clear at present, but the change in preferred orientation to (004) for N-TNAs should not be due to N atom incorporation, which usually coincides with the shift of the XRD peak [23,45]; meanwhile, the (004)-dominant orientation was also found in TNAs (without N-doping) prepared by one-step or two-step anodization [43]. Recently, the intrinsic electric fields were found to be responsible for the oriented self-assembly of multilevel branched rutile-type TiO 2 structures [46].…”

Section: Resultsmentioning

confidence: 99%

“…Jeon et al [29] successfully developed three-dimensional nanostructured N-doped TiO 2 monolith with enhanced visible light absorption, where the N-doping was obtained by thermal annealing of as-prepared 3D nanostructured TiO 2 with a thin TiN layer coating on the surface. Recently, highly ordered TNAs with diverse top-layer morphology and enhanced photoelectrochemical and photocatalytic activity were obtained using the two-step anodization [31,40,41,42,43,44]. Based on these findings in the literature, we postulate that the synergetic effects of N-doping, modified morphology, and high-crystallinity TNAs can be achieved by using simple thermal annealing under controlled N 2 gas flows.…”

Section: Introductionmentioning

confidence: 83%

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Enhanced Photocatalytic Performance of Nitrogen-Doped TiO2 Nanotube Arrays Using a Simple Annealing Process

Hiếu

Lam

et al. 2018

Micromachines

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Nitrogen-doped TiO2 nanotube arrays (N-TNAs) were successfully fabricated by a simple thermal annealing process in ambient N2 gas at 450 °C for 3 h. TNAs with modified morphologies were prepared by a two-step anodization using an aqueous NH4F/ethylene glycol solution. The N-doping concentration (0–9.47 at %) can be varied by controlling N2 gas flow rates between 0 and 500 cc/min during the annealing process. Photocatalytic performance of as-prepared TNAs and N-TNAs was studied by monitoring the methylene blue degradation under visible light (λ ≥ 400 nm) illumination at 120 mW·cm−2. N-TNAs exhibited appreciably enhanced photocatalytic activity as compared to TNAs. The reaction rate constant for N-TNAs (9.47 at % N) reached 0.26 h−1, which was a 125% improvement over that of TNAs (0.115 h−1). The significant enhanced photocatalytic activity of N-TNAs over TNAs is attributed to the synergistic effects of (1) a reduced band gap associated with the introduction of N-doping states to serve as carrier reservoir, and (2) a reduced electron‒hole recombination rate.

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Section: Resultsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 83%

Enhanced Photocatalytic Performance of Nitrogen-Doped TiO2 Nanotube Arrays Using a Simple Annealing Process

Hiếu

Lam

et al. 2018

Micromachines

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“…Therefore, they should be adequately treated before discharge to the environment [2]. Photoelectrocatalytic (PEC) method is a kind of advanced oxidation process (AOPs) which could effectively and efficiently degrade organic pollutants [1][2][3][4][5][6][7][8][9][10][11][12] during anodic and cathodic half-reactions [10,11]. PEC technology has a variety of advantages in comparison with other AOPs.…”

Section: Introductionmentioning

confidence: 99%

Analysis of the factors controlling the performance of a photoelectrocatalytic cell separated by UF membrane in degrading methylene blue

2020

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Methylene blue (MB) is a toxic and colorful organic matter that exists in the wastewater of textile industries. Difficult biodegradability of MB causes biological treatment methods that cannot sufficiently biodegrade it. In photoelectrocatalytic (PEC) methods, by converting the radiation energy to the electricity, MB is degraded efficiently in the anolyte chamber. Using the ultrafiltration (UF) membrane rather than a high-priced cation exchange membrane (CEM) decreases the cost of the PEC pilot. Therefore, in this study, different dependent and independent variables that affect the performance of the PEC are investigated to evaluate the technical feasibility of using ultra-filtration membrane as a separator of anode and cathode chambers. The results demonstrate an increase in the anolyte MB concentration up to 15 mg/l augments the PEC performance. In the best condition, the MB, turbidity, and color removal percent are 51.56%, 65.62%, and 64.19%, respectively, and produced power is 1.075 μW when the anolyte MB concentration, the pH, and the illumination density are 15 mg/l, 3, and 12 W, respectively. Also, the results indicate the removal percentage of the MB, turbidity, and color in either anolyte or catholyte rises in the anolyte acidic conditions and higher illumination densities. Besides, the changes in the EC and pH of anode and cathode chambers during the experiment are investigated, and finally, the relations between MB, color, and turbidity removal percentage are evaluated. As a result, it is found that the UF membrane is a suitable candidate to be used in PEC pilots.

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“…[1][2][3][4][5] The most common method to prepare extremely ordered porous structures like vertically aligned nanotubes is based the use of hard templates such as anodized aluminum oxide (AAO) membranes. [6][7][8][9][10] However, the main drawback of such approach is that it needs a multi-step process to obtain nanotubes and each nanotube characteristics requires the use of different membrane which complicate the implementation.…”

Section: Introductionmentioning

confidence: 99%

Templateless Electropolymerization for Controlled Growth of Polymeric Nanotubes on Micropatterned Surfaces

et al. 2019

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Controlling the growth of nanostructures on surfaces is fundamental to develop new materials for various fields of applications such as sensing or biomedical applications. Here, we study for the first time the influence of micropatterned substrates on the growth of nanotubes using a templateless electropolymerization approach. The influence of both the nature of the monomer and the deposition charge used in the polymerization process is assessed along with geometric parameters of the microstructured surfaces composed of bidimensionally distributed squared micropillars. First, we show that the formation of nanotubes is always favored at the basis of the microfeatures rather than on their top surface. As a consequence, it is preferable to avoid using monomers which lead to mono‐directional (1D) nanotube growth which would be only generated at the basis of the micropillars. By contrast, monomers leading to extremely short nanotubes (nanocups) are preferred. In addition, we hereby demonstrate that the surface coverage with the nanotubes is highly dependent on the geometric parameters of micropatterned substrates. Indeed, the growth of the nanostructures over the micropillars requires a significant energy and thus micropillars of lower height give optimal results. We demonstrate that it is possible to obtain a complete coverage of the microstructured substrate at even very low deposition charge applied during the electropolymerization step.

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Study of the highly ordered TiO2 nanotubes physical properties prepared with two-step anodization

Cited by 35 publications

References 26 publications

Enhanced Photocatalytic Performance of Nitrogen-Doped TiO2 Nanotube Arrays Using a Simple Annealing Process

Enhanced Photocatalytic Performance of Nitrogen-Doped TiO2 Nanotube Arrays Using a Simple Annealing Process

Analysis of the factors controlling the performance of a photoelectrocatalytic cell separated by UF membrane in degrading methylene blue

Templateless Electropolymerization for Controlled Growth of Polymeric Nanotubes on Micropatterned Surfaces

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