Influence of Prior Passivation on Characteristics of TiO2 Nanotube Arrays Fabricated on Ti Foil in a HF+H2SO4 Solution

摘要

In this study, we fabricated self-ordered TiO2 nanotube arrays (TNTs) by anodizing Ti foil with an initial passivation before the main anodic nanotube growth in a HF+H2SO4 solution. The effects of passivation potentials and pH values on TNTs were detected by SEM, AES, Raman spectra and Mott-Schottky plots. The thicknesses of barrier films increased linearly as the passivation potentials increased, and decreased linearly as pH values decreased. Moreover, the crystalline degrees of TNTs improved by increasing passivation potentials. Mott-Schottky plots demonstrated that donor densities of TNTs decreased with increasing passivation potentials and with decreasing pH values. (C) 2018 The Electrochemical Society.