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Fabrication of complete titania nanoporous structures via electrochemical anodization of Ti.

Ali G, Chen C, Yoo SH, Kum JM, Cho SO - Nanoscale Res Lett (2011)

Bottom Line: However, a complete titania nano-porous (TNP) structures are obtained when the second anodization is conducted in a viscous electrolyte when compared to the first one.The average pore diameter is approximately 70 nm, while the average inter-pore distance is approximately 130 nm.These TNP structures are useful to fabricate other nanostructure materials and nanodevices.

View Article: PubMed Central - HTML - PubMed

Affiliation: Department of Nuclear and Quantum Engineering, Korea Advanced Institute of Science and Technology (KAIST), 373-1 Guseong, Yuseong, Daejeon 305-701, Republic of Korea. socho@kaist.ac.kr.

ABSTRACT
We present a novel method to fabricate complete and highly oriented anodic titanium oxide (ATO) nano-porous structures with uniform and parallel nanochannels. ATO nano-porous structures are fabricated by anodizing a Ti-foil in two different organic viscous electrolytes at room temperature using a two-step anodizing method. TiO2 nanotubes covered with a few nanometer thin nano-porous layer is produced when the first and the second anodization are carried out in the same electrolyte. However, a complete titania nano-porous (TNP) structures are obtained when the second anodization is conducted in a viscous electrolyte when compared to the first one. TNP structure was attributed to the suppression of F-rich layer dissolution between the cell boundaries in the viscous electrolyte. The structural morphologies were examined by field emission scanning electron microscope. The average pore diameter is approximately 70 nm, while the average inter-pore distance is approximately 130 nm. These TNP structures are useful to fabricate other nanostructure materials and nanodevices.

No MeSH data available.


Related in: MedlinePlus

FESEM images of TiO2 nanotubes fabricated in EG containing 0.5 wt% NH4F and 0.2 wt% H2O via second-step anodization: (a) top surface view at low magnification, (b) top surface view at high magnification, (c) cross-sectional view.
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Figure 3: FESEM images of TiO2 nanotubes fabricated in EG containing 0.5 wt% NH4F and 0.2 wt% H2O via second-step anodization: (a) top surface view at low magnification, (b) top surface view at high magnification, (c) cross-sectional view.

Mentions: The top and the cross-sectional surface morphologies of TNT obtained after the second-step anodization in EG-based electrolyte are shown in Figure 3. The top surface topologies of the TiO2 nanotubes at a low- and a high-magnification are shown in Figure 3a,b, respectively, without a post-anodizing treatment. Highly ordered TiO2 nanotube arrays with open mouths are clearly visible in the images in spite of 20 h anodization. This is attributed to the honeycomb-like patterned morphology of Ti-substrate (Figure 2d), which not only protects the TiO2 nanotubes from sealing and bundling but also produces TiO2 nanotubes with uniform heights. The honeycomb-like patterned morphology of individual hexagonal ring is clearly reflected in the magnified image (hexagonal marked pores in Figure 3b); however, the hexagonal shape geometry of individual concave nano-dimples is slightly distorted in some area due to a longer anodization time. The formation of a thin nano-porous layer on the top surface of TiO2 nanotubes is evident from the areas marked with circles, where nanotubes wall can be clearly seen inside nanopores. This result is also verified from the cross-sectional image of the nanotubes (Figure 3c), where nanotubes are connected with each other via a thin nanoporous layer. These results indicate that the formation of nanotubes is initiated exactly below the honeycomb-like patterned morphology during the second-step anodization and act as a template for further growth of nanotubes; however, appearance of the nanotubes wall inside the nanopores (Figure 3b) also suggests slight deviations. These results also reveal that nanopores have almost uniform diameters and that nanotubes walls are very smooth throughout their entire lengths.


Fabrication of complete titania nanoporous structures via electrochemical anodization of Ti.

Ali G, Chen C, Yoo SH, Kum JM, Cho SO - Nanoscale Res Lett (2011)

FESEM images of TiO2 nanotubes fabricated in EG containing 0.5 wt% NH4F and 0.2 wt% H2O via second-step anodization: (a) top surface view at low magnification, (b) top surface view at high magnification, (c) cross-sectional view.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC3211420&req=5

Figure 3: FESEM images of TiO2 nanotubes fabricated in EG containing 0.5 wt% NH4F and 0.2 wt% H2O via second-step anodization: (a) top surface view at low magnification, (b) top surface view at high magnification, (c) cross-sectional view.
Mentions: The top and the cross-sectional surface morphologies of TNT obtained after the second-step anodization in EG-based electrolyte are shown in Figure 3. The top surface topologies of the TiO2 nanotubes at a low- and a high-magnification are shown in Figure 3a,b, respectively, without a post-anodizing treatment. Highly ordered TiO2 nanotube arrays with open mouths are clearly visible in the images in spite of 20 h anodization. This is attributed to the honeycomb-like patterned morphology of Ti-substrate (Figure 2d), which not only protects the TiO2 nanotubes from sealing and bundling but also produces TiO2 nanotubes with uniform heights. The honeycomb-like patterned morphology of individual hexagonal ring is clearly reflected in the magnified image (hexagonal marked pores in Figure 3b); however, the hexagonal shape geometry of individual concave nano-dimples is slightly distorted in some area due to a longer anodization time. The formation of a thin nano-porous layer on the top surface of TiO2 nanotubes is evident from the areas marked with circles, where nanotubes wall can be clearly seen inside nanopores. This result is also verified from the cross-sectional image of the nanotubes (Figure 3c), where nanotubes are connected with each other via a thin nanoporous layer. These results indicate that the formation of nanotubes is initiated exactly below the honeycomb-like patterned morphology during the second-step anodization and act as a template for further growth of nanotubes; however, appearance of the nanotubes wall inside the nanopores (Figure 3b) also suggests slight deviations. These results also reveal that nanopores have almost uniform diameters and that nanotubes walls are very smooth throughout their entire lengths.

Bottom Line: However, a complete titania nano-porous (TNP) structures are obtained when the second anodization is conducted in a viscous electrolyte when compared to the first one.The average pore diameter is approximately 70 nm, while the average inter-pore distance is approximately 130 nm.These TNP structures are useful to fabricate other nanostructure materials and nanodevices.

View Article: PubMed Central - HTML - PubMed

Affiliation: Department of Nuclear and Quantum Engineering, Korea Advanced Institute of Science and Technology (KAIST), 373-1 Guseong, Yuseong, Daejeon 305-701, Republic of Korea. socho@kaist.ac.kr.

ABSTRACT
We present a novel method to fabricate complete and highly oriented anodic titanium oxide (ATO) nano-porous structures with uniform and parallel nanochannels. ATO nano-porous structures are fabricated by anodizing a Ti-foil in two different organic viscous electrolytes at room temperature using a two-step anodizing method. TiO2 nanotubes covered with a few nanometer thin nano-porous layer is produced when the first and the second anodization are carried out in the same electrolyte. However, a complete titania nano-porous (TNP) structures are obtained when the second anodization is conducted in a viscous electrolyte when compared to the first one. TNP structure was attributed to the suppression of F-rich layer dissolution between the cell boundaries in the viscous electrolyte. The structural morphologies were examined by field emission scanning electron microscope. The average pore diameter is approximately 70 nm, while the average inter-pore distance is approximately 130 nm. These TNP structures are useful to fabricate other nanostructure materials and nanodevices.

No MeSH data available.


Related in: MedlinePlus