Anodic formation of nanoporous and nanotubular metal oxides

Su, Zixue; Zhou, Wuzong; Jiang, Feilong; Hong, Maochun

doi:10.1039/c1jm13338a

Cited by 63 publications

(60 citation statements)

References 65 publications

(69 reference statements)

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“…It is worth noting that oxygen bubbles have been proposed to be generated (TiO 2 → Ti 4+ + O 2 + 4e − ) during the vigorous anodic growth [23,24]. Consequently, bubble growth and coalescence are responsible for the formation of oxygen filled cavities at tube boundaries [24]. A close view of the nanotubes displays strong evidence of gas bubbles generated in the anodizing process.…”

Section: Morphology and Structural Characterizationmentioning

confidence: 99%

Enhanced supercapacitance in anodic TiO₂nanotube films by hydrogen plasma treatment

et al. 2013

Nanotechnology

131

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One-dimensional anodic titanium oxide (ATO) nanotube arrays hold great potential as electrode materials for high-performance electrochemical supercapacitors. However, their poor electronic conductivity limits their practical applications. Here, we develop a hydrogen (H2) plasma treatment method to greatly improve the electrochemical performance of ATO electrodes. Compared with pristine ATO, the nanotubes treated by H2 plasma illumination (ATO-H) present a rough and amorphous layer at the surface of the nanotubes with simultaneously incorporated Ti(3+) and -OH groups. At a current density of 0.05 mA cm(-2) in charge-discharge measurements, the specific capacitance of the ATO-H electrode has substantially increased ~7.4 times, with a value as high as 7.22 mF cm(-2). Moreover, the novel ATO-H electrode has also exhibited excellent rate capability (6.37 mF cm(-2) at a current density of 2 mA cm(-2)) and cycling performance with no degradation after 10,000 cycles.

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Section: Morphology and Structural Characterizationmentioning

confidence: 99%

Enhanced supercapacitance in anodic TiO₂nanotube films by hydrogen plasma treatment

et al. 2013

Nanotechnology

131

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“…where, T 1 is the time when the barrier oxide in part l 1 reaches the critical thickness, l c1 /T 1 is the average growth rate. When comparing equation (8) with (7), we can easily obtain:…”

Section: Theoretical Derivation Of Ionic Current and Electronic Currentmentioning

confidence: 99%

Theoretical derivation of anodizing current and comparison between fitted curves and measured curves under different conditions

et al. 2015

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Anodic TiO2 nanotubes have been studied extensively for many years. However, the growth kinetics still remains unclear. The systematic study of the current transient under constant anodizing voltage has not been mentioned in the original literature. Here, a derivation and its corresponding theoretical formula are proposed to overcome this challenge. In this paper, the theoretical expressions for the time dependent ionic current and electronic current are derived to explore the anodizing process of Ti. The anodizing current-time curves under different anodizing voltages and different temperatures are experimentally investigated in the anodization of Ti. Furthermore, the quantitative relationship between the thickness of the barrier layer and anodizing time, and the relationships between the ionic/electronic current and temperatures are proposed in this paper. All of the current-transient plots can be fitted consistently by the proposed theoretical expressions. Additionally, it is the first time that the coefficient A of the exponential relationship (ionic current j(ion) = A exp(BE)) has been determined under various temperatures and voltages. And the results indicate that as temperature and voltage increase, ionic current and electronic current both increase. The temperature has a larger effect on electronic current than ionic current. These results can promote the research of kinetics from a qualitative to quantitative level.

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“…When the voltage is stepped down to 20 V, the oxide growth may entirely stop and the barrier layer will be thinned due to chemical etching in the fluoride solution 12. The oxide at the cell boundary suffers a higher chemical dissolution than the oxide at the tube bottom, due to the accumulation of oxygen filled voids 13, fluoride 14 and mechanical stress 9. After exposure to the etching electrolyte for a while, the oxide at the cell boundary is thinner than the oxide at the tube bottom.…”

Section: Resultsmentioning

confidence: 99%

Experimental observation of two‐layer TiO₂ nanotube arrays prepared by stepping‐voltage anodization

Ding

Xiao

Fan

2012

Physica Rapid Research Ltrs

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Two‐layer TiO2 nanotube arrays were produced by stepping down the anodic voltage during which three nanotube interface structures between the top layer and the second layer were observed by SEM. We detected a polygonal ring structure on the top surface of the second layer and offer direct evidence of the growth of this second tube layer both at the cell boundary and right beneath the bottom of the first tube layer. For these processes, a possible growth mechanism is presented. (© 2012 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)

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Anodic formation of nanoporous and nanotubular metal oxides

Cited by 63 publications

References 65 publications

Enhanced supercapacitance in anodic TiO₂nanotube films by hydrogen plasma treatment

Enhanced supercapacitance in anodic TiO₂nanotube films by hydrogen plasma treatment

Theoretical derivation of anodizing current and comparison between fitted curves and measured curves under different conditions

Experimental observation of two‐layer TiO₂ nanotube arrays prepared by stepping‐voltage anodization

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Anodic formation of nanoporous and nanotubular metal oxides

Cited by 63 publications

References 65 publications

Enhanced supercapacitance in anodic TiO2nanotube films by hydrogen plasma treatment

Enhanced supercapacitance in anodic TiO2nanotube films by hydrogen plasma treatment

Theoretical derivation of anodizing current and comparison between fitted curves and measured curves under different conditions

Experimental observation of two‐layer TiO2 nanotube arrays prepared by stepping‐voltage anodization

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Product

Resources

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Enhanced supercapacitance in anodic TiO₂nanotube films by hydrogen plasma treatment

Enhanced supercapacitance in anodic TiO₂nanotube films by hydrogen plasma treatment

Experimental observation of two‐layer TiO₂ nanotube arrays prepared by stepping‐voltage anodization