Titania nanotubes from pulse anodization of titanium foils

• Published in: Electrochemistry communications 2007-08, Vol.9 (8), p.2145-2149
• Main Authors: Chanmanee, Wilaiwan, Watcharenwong, Apichon, Chenthamarakshan, C. Ramannair, Kajitvichyanukul, Puangrat, de Tacconi, Norma R., Rajeshwar, Krishnan
• Format: Article
• Language: English
• Subjects: Applied sciences; Chemistry; Electrochemistry; Energy; Exact sciences and technology; General and physical chemistry; Nanotube arrays; Natural energy; Photoelectrochemical response; Photoelectrochemistry. Electrochemiluminescence; Photovoltaic conversion; Pulse anodization; Solar cells. Photoelectrochemical cells; Solar energy
• ISSN: 1388-2481; 1873-1902
• DOI: 10.1016/j.elecom.2007.06.006

A pulse waveform for the anodic growth of TiO 2 nanotube arrays is described. The arrays were grown on Ti foil substrate using a 20 V/−4 V pulse sequence in NH 4F electrolyte in neat water or glycerol containing 1% water. The pulse anodization approach yielded superior nanotube morphology and photocurrent response (in Na 2SO 4 supporting electrolyte) relative to samples grown via the conventional, continuous anodization method. Further, the results from this study provide crucial supporting evidence for mechanistic models of anodic growth and self-assembly of oxide nanotube arrays on the parent metal surface. Specifically, adsorption of NH 4 + species on the TiO 2 surface that is promoted by the negative voltage pulse is shown to ameliorate the extent of chemical attack of the growing oxide nanoarchitecture by the electrolyte F − species, resulting in better nanotube morphology.