Organic and inorganic surface passivations of TiO2 nanotube arrays for dye-sensitized photoelectrodes

Park, Hun; Yang, Changduk; Choi, Won‐Youl

doi:10.1016/j.jpowsour.2012.05.060

Cited by 22 publications

(9 citation statements)

References 31 publications

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“…Recent advances in the fabrication, properties, and applications of TiO 2 nanotube arrays have provided new opportunities for research in relation to their use in clinical practice. (Mor et al 2006;Ghicov and Schmuki 2009;Mun et al 2010;Park et al 2012;Kim et al 2014) Park et al (Park et al 2007 reported that anodized titanium implants showed rougher surface, higher removal torque, and higher bone-to-implant contact than nonanodized implants. Anodic oxidation on Ti surfaces increases the surface roughness, and the resultant TiO 2 nanotube structures are known to have an encouraging effect on cell behavior, such as adhesion, migration, survival, and differentiation (Minagar et al 2013).…”

Section: Introductionmentioning

confidence: 99%

Effect of TiO2 nanotubes arrays on osseointegration of orthodontic miniscrew

Jang

Shim

Choi

et al. 2015

Biomed Microdevices

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To increase the stability of orthodontic miniscrews, TiO2 nanotube arrays were fabricated on the surface of Ti miniscrews and the effect of those arrays on the osseointegration of miniscrews was evaluated. Highly ordered TiO2 nanotube arrays were grown on the surface of orthodontic miniscrews. Ethylene glycol based electrolyte was used in the anodic oxidation process. Two-step anodic oxidation was conducted to obtain clean and open windows in TiO2 nanotube arrays. The diameter and length of the TiO2 nanotube arrays were ~ 70 nm and ~ 5 μm, respectively. The miniscrews with TiO2 nanotube arrays were implanted in the legs of New Zealand white rabbits for 8 weeks. Histological osseointegration was assessed by bone-to-implant contact ratio, and three-dimensional bone volume ratio was measured by micro-computed tomography analysis. The miniscrews with TiO2 nanotube arrays had a greater mean bone-to-implant contact ratio of 52.8 % than the control, 29.3 %. Mean bone volume ratio (BV/TV) was also higher in the miniscrews with TiO2 nanotube arrays, at 81.2 % than those in the control via micro-CT analysis. Our findings support that TiO2 nanotube arrays on the surface of miniscrews enhance osseointegration and improve the stability of the miniscrew.

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Section: Introductionmentioning

confidence: 99%

Effect of TiO2 nanotubes arrays on osseointegration of orthodontic miniscrew

Jang

Shim

Choi

et al. 2015

Biomed Microdevices

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“…The effort to find alternative TiO 2 nanostructures has been an important issue to researchers who attempt to increase the power conversion efficiency of DSCs. Various types of nanotechnologies have been applied to alternative TiO 2 nanostructures such as nanorods [ 13 ], nanowires [ 14 , 15 ], nanotubes [ 16 , 18 , 19 , 22 , 23 , 25 , 27 - 30 , 42 ], [ 43 ], nanohemispheres [ 21 , 24 ], and nanoforests [ 17 , 20 ]. These structures were used to increase the surface area for dye adsorption and to facilitate charge transport through TiO 2 films.…”

Section: Introductionmentioning

confidence: 99%

TiO2 micro-flowers composed of nanotubes and their application to dye-sensitized solar cells

2014

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TiO2 micro-flowers were made to bloom on Ti foil by the anodic oxidation of Ti-protruding dots with a cylindrical shape. Arrays of the Ti-protruding dots were prepared by photolithography, which consisted of coating the photoresists, attaching a patterned mask, illuminating with UV light, etching the Ti surface by reactive ion etching (RIE), and stripping the photoresist on the Ti foil. The procedure for the blooming of the TiO2 micro-flowers was analyzed by field emission scanning electron microscopy (FESEM) as the anodizing time was increased. Photoelectrodes of dye-sensitized solar cells (DSCs) were fabricated using TiO2 micro-flowers. Bare TiO2 nanotube arrays were used for reference samples. The short-circuit current (Jsc) and the power conversion efficiency of the DSCs based on the TiO2 micro-flowers were 4.340 mA/cm2 and 1.517%, respectively. These values of DSCs based on TiO2 micro-flowers were higher than those of bare samples. The TiO2 micro-flowers had a larger surface area for dye adsorption compared to bare TiO2 nanotube arrays, resulting in improved Jsc characteristics. The structure of the TiO2 micro-flowers allowed it to adsorb dyes very effectively, also demonstrating the potential to achieve higher power conversion efficiency levels for DSCs compared to a bare TiO2 nanotube array structure and the conventional TiO2 nanoparticle structure.

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“…The film/substrate contact is the essential routine for the electron collection, [3][4][5] and the cell performance is believed to be increased with the improvement of film/substrate contact. [6][7][8] However, the effect of the film/substrate interface on the cell performance is not clear yet.…”

Section: Introductionmentioning

confidence: 99%

“…[36][37][38] However, the film/substrate contact is considered to only influence its corresponding and independent column in film according to this theoretical assumption. [20][21][22][23][24] Although the typical equivalent circuit model seems to explain the electron transferring through the high-temperature sintered film/substrate interface, [6][7][8] the influence of the film/substrate contact has yet to be completely illuminated.…”

Section: Introductionmentioning

confidence: 99%

Influence of TiO<SUB>2</SUB> Film/Substrate Contact on Photovoltaic Performance and Improved Efficiency in Dye-Sensitized Solar Cells

Hai‐Long¹,

Yang²,

Li³

et al. 2016

j nanosci nanotechnol

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The influence of the nano-porous TiO 2 film/FTO substrate contact on the photovoltaic performance of dye-sensitized solar cells is investigated by controlling film/FTO substrate contact through the use of insulating Al 2 O 3 clusters and TiO 2 underlayer at the interface. The electrochemical properties of the DSCs are examined to correlate the photovoltaic performance and the film/FTO substrate contact condition. Results show that the short-circuit current density and thereby the photo-to-electric energy conversion efficiency of the DSCs are significantly decreased by increasing Al 2 O 3 clusters coverage ratio. A modified equivalent circuit model is proposed to understand the relationship between the electric contact resistance and short-circuit current density. Although the increased electric contact resistance itself presents no significant effect on the photovoltaic performance, the decreased performance is mainly attributed to the decreased electron collection in the cell due to the presence of Al 2 O 3 clusters at the film/FTO substrate interface. The result reveals that the film/substrate contact should not be negligible, even though the electric contact resistance of this interface can be neglected. The mechanism by which the film/FTO substrate contact affects cells performance reveals that the porous film cannot be considered as independent column structure but as a network structure being able to transfer electron both perpendicularly and laterally. A spraydeposited TiO 2 underlayer was applied to improve the film/FTO substrate interface contact resulting in an increased J sc and thereby a higher energy conversion efficiency.

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Organic and inorganic surface passivations of TiO2 nanotube arrays for dye-sensitized photoelectrodes

Cited by 22 publications

References 31 publications

Effect of TiO2 nanotubes arrays on osseointegration of orthodontic miniscrew

Effect of TiO2 nanotubes arrays on osseointegration of orthodontic miniscrew

TiO2 micro-flowers composed of nanotubes and their application to dye-sensitized solar cells

Influence of TiO<SUB>2</SUB> Film/Substrate Contact on Photovoltaic Performance and Improved Efficiency in Dye-Sensitized Solar Cells

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