Photogenerated cathodic protection properties of Fe2O3 nanotubes prepared by anodic oxidation

Abstract

Photogenerated cathodic protection as a new type of corrosion protection method has evoked great attention. The n-type semiconductor is normally selected as the photogenerated cathodic protection composite. α-Fe2O3 is a typical n-type semiconductor, which is easy to obtain and environmental-friendly. However, it is normally prepared on the FTO substrate and could hardly protect carbon steel. In this study, α-Fe2O3 nanotubes are fabricated on carbon steel by anodic oxidation method at different oxidation potentials. The corresponding surface morphologies, compositions, and optical absorption properties are characterized with SEM, Raman spectroscopy, and UV-Visible spectrometer. The photoelectrochemical tests show that the prepared α-Fe2O3 can supply cathodic protection to carbon steel. The maximum photogenerated potential drop is obtained for the α-Fe2O3 sample prepared under 50 V at 30 ℃ for 450 s anodic oxidation. It is revealed that the fine structure is benefit to capture light and enhances the photogenerated cathodic protection performance to carbon steel.