Enhanced Photoelectrochemical Properties of Fe-TiO2 Nanotube Films: A Combined Experimental and Theoretical Study

Fe-doped TiO2 nanotube array (Fe-TiO2 TNTA) films are produced by a simple and facile anodization method on Ti foil substrates. The Fe-doped TNTA films were characterized by SEM, Raman, XPS and UV–vis spectrum. The result showed that the absorption edge generated bathochromic shift. Raman and XPS reveal that Ti4+ ions were uniformly substituted by Fe3+ ions or Ti-O-Fe bonds. After comparing different Fe3+ ions concentrations, 0.1M Fe-doped TiO2 samples exhibite the highest photocurrent value, indicating super photoelectrochemical activity. The difference between the photocathodic protection properties of TNTA films and Fe-doped TNTA films is also investigated. The The density functional theory (DFT) calculation is carried out to confirm the effects of the Fe3+ ions on the absorption edge redshift and the bandgap changes.