Development Of Carbon And Potassium-Incorporated Titanium Dioxide Nanotube Arrays For Solar Energy Harvesting Applications
Loading...
Date
2013-05
Authors
Krengvirat, Warapong
Journal Title
Journal ISSN
Volume Title
Publisher
Universiti Sains Malaysia
Abstract
TiO2 nanotube arrays have attracted great interest as the most promising candidate for solar energy harvesting applications. However, poor visible-light absorption and high recombination of charge carriers still remain as challenging issues for their practical applications. Hence, the objective of this work was to develop carbon and potassium-incorporated TiO2 nanotube arrays for solar energy harvesting applications, including photodecolorization, photoelectrochemical cell (PEC) and dye-sensitized solar cells (DSSC). Visible-light responsive TiO2 nanotube arrays were rapidly grown with a rate of ~289 nm min-1 by anodic oxidation in ethylene glycol (EG) containing 0.5 wt% ammonium fluoride (NH4F) and 1 wt% H2O. The presence of adsorbed-carbonate species and interstitial carbon in TiO2 nanotubes originated from the pyrogenation of EG resulted in the generation of localized state, and thus enabled the visible-light absorption. Anatase TiO2 nanotube arrays with high surface area (110.9 m2 g-1) were obtained by facile immersion of as-anodized nanotube arrays in hot water at ~90C. Such hot water-treated nanotube arrays exhibited efficient visible-light photodegradation of methylene blue with the decomposition rate of ~11 % h-1. This value is relatively higher than heat-treated arrays (~9 % h-1) and P25 powder (~2 % h-1). However, heat treatment at 400C for 4 h was found as essential approach to obtain better crystallinity for high PEC and DSSC properties.
Description
Keywords
Carbon And Potassium-Incorporated Titanium Dioxide Nanotube Arrays , Solar Energy Harvesting Applications