Optimization of Nanostructure and Characterization: Anodization of TiO₂ in the Polyethylene Glycol-Based Electrolyte

The homogeneity and stability of the structure of anodic TiO₂ nanotube (ATNT) arrays have been a hot topic in materials synthesis research. In this work, the current density distribution during the anodization of ATNT arrays was optimized by adding polyethylene glycol-600 (PEG-600) to the conventional ethylene glycol-based electrolyte, which enhanced the dependence of the electronic current on the applied voltage, thus providing a stabilizing effect on anodization and improving the homogeneity of the pores on the surface of ATNT arrays. A new image processing approach, called the region-growing method, is reported in this work, which can quantitatively analyze the pore size of ATNT arrays through SEM images, and the surface morphology of ATNT arrays was evaluated based on this. The most stable anodization was obtained with a 50 wt % PEG-600 addition, and the equivalent diameters of the pores prepared at applied voltages of 40, 50, and 60 V were 34.5340, 42.4010, and 50.4791 nm, respectively, with a linear correlation of 0.9999.