Effect of electrolyte conductivity on the formation of a nanotubular TiO ₂ photoanode for a dye-sensitized solar cell

Ordered TiO ₂ nanotube arrays can be prepared by anodizing of Ti metal. However, the nanotubular TiO ₂ structure shows a lack of reproducibility when the Ti metal is repetitively anodized in a prepared solution. The TiO ₂ tube length increases as the number of anodizations increases. In this work, the effects of the solution conductivity and temperature on the formation of the nanotubular TiO ₂ structure were analyzed using the measured current transients and tube morphology. Nanotubular TiO ₂ was tested as an anode for a dye-sensitized solar cell and its performance was interpreted using electrochemical impedance spectroscopy in relation to a morphological study of the TiO ₂ structure.