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International Journal of Photoenergy
Volume 2013, Article ID 276504, 8 pages
http://dx.doi.org/10.1155/2013/276504
Research Article

Single Step Formation of C-TiO2 Nanotubes: Influence of Applied Voltage and Their Photocatalytic Activity under Solar Illumination

1Nanotechnology & Catalysis Research Centre (NANOCAT), Institute of Postgraduate Studies (IPS), Universiti Malaya, 3rd Floor, Block A, 50603 Kuala Lumpur, Malaysia
2School of Materials and Mineral Resources Engineering, Universiti Sains Malaysia Engineering Campus, Seberang Perai Selatan, Pulau Pinang, 14300 Nibong Tebal, Malaysia

Received 25 June 2013; Revised 29 September 2013; Accepted 7 October 2013

Academic Editor: Huogen Yu

Copyright © 2013 Chin Wei Lai and Srimala Sreekantan. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

Abstract

Self-aligned and high-uniformity carbon (C)- titania (TiO2) nanotube arrays were successfully formed via single step anodization of titanium (Ti) foil at 30 V for 1 h in a bath composed of ethylene glycol (EG), ammonium fluoride (NH4F), and hydrogen peroxide (H2O2). It was well established that applied voltage played an important role in controlling field-assisted oxidation and field-assisted dissolution during electrochemical anodization process. Therefore, the influences of applied voltage on the formation of C-TiO2 nanotube arrays were discussed. It was found that a minimal applied voltage of 30 V was required to form the self-aligned and high-uniformity C-TiO2 nanotube arrays with diameter of ~75 nm and length of ~2 μm. The samples synthesized using different applied voltages were then subjected to heat treatment for the conversion of amorphous phase to crystalline phase. The photocatalytic activity evaluation of C-TiO2 samples was made under degradation of organic dye (methyl orange (MO) solution). The results revealed that controlled nanoarchitecture C-TiO2 photocatalyst led to a significant enhancement in photocatalytic activity due to the creation of more specific active surface areas for incident photons absorption from the solar illumination.