Fabrication and Characterization of an Anodic Aluminum Oxide Template with Variations in the Anodization Solution for pH Sensors

Abstract

In this study, an electrolyte-dielectric-metal (EDM) device incorporating a high-k (high dielectric constant) Al2O3 sensing template from porous anodic aluminum-oxide (AAO) was fabricated through a two-step anodizing process for pH detection. In order to change the morphologies of the AAO template, the anodization solution was varied by controlling the electrolyte. Getting the AAO template having a structure through this experiment was EDM measure the pH sensitivity changes according to the surface area. AAO templates were characterized by X-ray diffraction and field-emission scanning electron microscopy (FE-SEM). The anodic aluminum oxide template for pH sensors went through the following steps: 1st anodizing step at 90 V for 6 h (0.3 M, H3PO4); 2nd anodizing step at 90 V for 1 min (H3PO4 0.3 M); and pore widening for 30 min. The device displayed a good sensitivity of 54.2 mV/pH.