PH sensors with TiO2Nanotubes fabricated with photoresist layer

Abstract

Optimized TiO <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> nanotubes arrays were obtained by the deposition of photoresist layers on the Ti foil prior to the anodization process. In this way the initial current during the anodization process decreases significantly, avoiding or diminishing the formation of the initial compact TiO <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> layer, also for long process times nanograss formation is avoided. TiO <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> nanotubes were obtained with the conventional process and with the addition of the photoresist layer different anodization voltages and times. TiO <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> nanotubes pH electrodes were fabricated to study the effect of this optimized process in sensors response. The nanostructures morphology was analyzed through scanning electron microscopy (SEM) technique. A total removal of the undesirable layer and a complete release of the nanotubes mouth were obtained. The pH electrodes where characterized utilizing a buffer solution, PH sensibility improved and absence of hysteresis effects were observed for the devices fabricated with TiO <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> nanotubes obtained with the optimized process.