Effect of Anions on the Electrochemical Formation of TiO<SUB>2</SUB> Nanotube Arrays in a Glycerol Based Electrolyte

Abstract

The formation of titania nanotubes was achieved by electrochemical anodization in glycerol based electrolytes. We investigated the effect of three anionic species, anodic time and NaAc concentration on the formation of TiO2 nanotubes. The choice of anion was found to be a key parameter influencing both the nanotube growth rate and the resultant nanotube length. Longer tube lengths were obtained by adding NaNO3 and NaCl, by increasing the current density and by increasing the electrochemical etching rate at tube's bottom. The current density and the electrochemical etching rate at the tube's bottom decreased with added NaAc. Electrolytes with added NaAc were much more efficient at producing longer nanotubes, by effectively slowing the chemical dissolution rate at the top of the tube.