Effect of increasing etchant concentration to accelerate synthesis of 9-µm-long TiO2 nanotubes

Nyasha J. Suliali; William E. Goosen; Johannes R. Botha

doi:10.1117/12.2327083

24 January 2019 Effect of increasing etchant concentration to accelerate synthesis of 9-μm-long TiO₂ nanotubes

Nyasha J. Suliali, William E. Goosen, Johannes R. Botha

Proceedings Volume 11043, Fifth Conference on Sensors, MEMS, and Electro-Optic Systems; 110430Q (2019) https://doi.org/10.1117/12.2327083
Event: Fifth Conference on Sensors, MEMS, and Electro-Optic Systems, 2018, Skukuza, South Africa

Abstract

During electro-deposition of a TiO₂ film on titanium foil, an etching agent supplies ionic species that create the desired morphology by chemical dissolution of the oxide layer. The etchant ions attack both titanium ions and the oxide film to form hexafluorotitanate complexes, water and hydroxyl species. In this study, an attempt was made to reduce the duration of a TiO₂ film electro-deposition process by increasing the chemical dissolution rate. Two 127 μm-thick titanium foil substrates were anodised for different durations in an anhydrous polar organic solvent containing different amounts of an etchant. This yielded 9 μm-long nanotubes. Anodisation current density measurements for a two hour process showed slow chemical dissolution when the amount of etchant was low. In an attempt to speed-up the electro-deposition process, the amount of etchant was increased and anodisation carried out for only an hour. This yielded films (consisting of nanotube arrays) that are equal in thickness to that obtained in the two hour process. However, scanning electron microscopy revealed un-etched regions of the film between the tubes when the etchant concentration is high. These fragments are dimensional irregularities in an otherwise uniform tubular structure and hence are defect sites that could reduce charge transport efficiency. The study shows that the nanotube array quality is reduced when the duration of the anodisation process is shortened by an increased etch rate, without further optimisation of the anodisation parameters.

Citation Download Citation

Nyasha J. Suliali, William E. Goosen, and Johannes R. Botha "Effect of increasing etchant concentration to accelerate synthesis of 9-μm-long TiO₂ nanotubes", Proc. SPIE 11043, Fifth Conference on Sensors, MEMS, and Electro-Optic Systems, 110430Q (24 January 2019); https://doi.org/10.1117/12.2327083

ACCESS THE FULL ARTICLE

INSTITUTIONAL
Select your institution to access the SPIE Digital Library.

SELECT YOUR INSTITUTION

PERSONAL
Sign in with your SPIE account to access your personal subscriptions or to use specific features such as save to my library, sign up for alerts, save searches, etc.

PERSONAL SIGN IN

No SPIE Account? Create one

PURCHASE THIS CONTENT

SUBSCRIBE TO DIGITAL LIBRARY

50 downloads per 1-year subscription

Members: $195

Non-members: $335 ADD TO CART

25 downloads per 1 - year subscription

Members: $145

Non-members: $250 ADD TO CART

PURCHASE SINGLE ARTICLE

Includes PDF, HTML & Video, when available