TiO_2 nanotubes were synthesized by anodic oxidation of titanium foils using dimethyl sulfoxide and hydrofluoric acid as the electrolyte. The electrical properties of individual nanotube-based devices were evaluated and modeled after exposing some of them to different gas and illumination conditions. Resistivity values fully comparable to those of TiO_2 single crystal anatase (ρSA = 1.09 ± 0.01Ω cm) were found, and their photoconductive characteristics, explained in terms of the Shockley-Read-Hall model for non-radiative recombination in semiconductors, were found to be strongly influenced by the applied experimental conditions such as the surrounding atmosphere. These devices may have potential applications in photocatalytic processes, such as CO_2 reduction or H_2O splitting, avoiding the interfering effects typical of nanotube arrays.
展开▼
