Effect of Electrolyte Concentration on the Morphology and Photoelectrochemical Response of Titania Nanotubes Prepared by Electrochemical Anodisation

Abstract:

In this work, the effect of NH₄F concentration on the formation, dimensions and photoelectrochemical response of titania nanotubes produced by anodisation of Ti in ethylene glycol has been investigated. The results showed that a minimum amount of 0.25 wt.% NH₄F is needed for the formation of uniform and ordered nanotubes in viscous ethylene glycol. Self-organized nanotubes can be synthesized in the concentration range of 0.250.7 wt.%; with a higher fluoride concentration leads to severe etching of the tube tops resulting in a grassy-like appearance. Varying the concentration of NH₄F has no effect on the tube diameter and wall thickness. However, nanotubes length increases gradually by increasing the NH₄F concentration with preferred growth along the c-axis. Thermal annealing at 500 °C transforms the amorphous nature of as-formed nanotubes into pure anatase phase. Photoelectrochemical response of nanotubes was tested with linear sweep photovoltammetry. It was found that microstructures, crystallinity and geometry of the nanotubes are important factors influencing the photoresponse.

• Periodical: Advanced Materials Research (Volume 832)
• Pages: 744-748
• DOI: https://doi.org/10.4028/www.scientific.net/AMR.832.744
• Online since: November 2013
• Authors: Yingchin Lim, Zulkarnain Zainal, Mohd Zobir Hussein, Weetee Tan
• Keywords: Anodisation, Ethylene Glycol, Nanotubes, Titania

References

[1] S. Rani, S. C. Roy, M. Paulose, O. K. Varghese, G. K. Mor, S. Kim, S. Yoriya, T. J. LaTempa, C. A. Grimes, Synthesis and applications of electrochemically self-assembled titania nanotube arrays, Phys. Chem. Chem. Phys. 12 (2010) 2780-2800.

DOI: 10.1039/b924125f

[2] C.A. Grimes, Synthesis and application of highly ordered arrays of TiO2 nanotubes, J. Mater. Chem. 17 (2007) 1451-1457.

DOI: 10.1039/b701168g

[3] P. Roy, D. Kim, K. Lee, E. Spiecker, P. Schmuki, TiO2 nanotubes and their application in dye-sensitized solar cells, Nanoscale 2 (2010) 45-49.

DOI: 10.1039/b9nr00131j

[4] K. C. Popat, L. Leoni, C. A. Grimes, T. A. Desai, Influence of engineered titania nanotubular surfaces on bone cells, Biomater. 28 (2007) 3188-3197.

DOI: 10.1016/j.biomaterials.2007.03.020

[5] Z. B. Xie, D. J. Blackwood, Effects of anodization parameters on the formation of titania nanotubes in ethylene glycol, Electrochimica Acta 56 (2010) 905-912.

DOI: 10.1016/j.electacta.2010.10.004

[6] Y. Yang, X. Wang, L.Li, Crystallization and phase transition of titanium oxide nanotube arrays, J. Amer. Chem. Soc. 91 (2008) 632-635.

[7] N. Liu, K. Lee, P. Schmuki, Small diameter TiO2 nanotubes vs. nanopore in dye sensitized solar cells, Electrochem. Commum. 15 (2012) 1-4.

DOI: 10.1016/j.elecom.2011.11.003