Synthesis and characterization of iron-doped titania nanohoneycomb and nanoporous semiconductors by electrochemical anodizing method as good visible light active photocatalysts

Iron-doped TiO2 nanostructures (FeTiO2NSs) were prepared by in situ electrochemical anodizing of titanium in a single-step process in the presence of 3, 9, 15 and 21 mM of potassium ferricyanide. For the first time, K3Fe(CN)6 was used as the iron source in doping process. The resulting samples were characterized by FE-SEM, XRD and EDX. SEM images of the resulting samples showed that for a specific morphology, appropriate concentrations of potassium ferricyanide are necessary. Diffuse reflectance spectra showed a shift toward longer wavelengths relative to pure TiO2 nanotube (TiO2NT). The dependence of photo-activity on iron doping on TiO2 was studied for photodegradation of methylene blue (MB). After iron-doping, the removal rate of MB increased under visible light radiation. The results showed that FeTiO2NSs samples have excellent photocatalytic performance. The sample FeTiO2NSs2 exhibited better photocatalytic activity than the pure TiO2NTs and FeTiO2NSs samples fabricated using other iron concentrations. This work demonstrated a feasible and simple anodizing method to fabricate an effective, reproducible, and inexpensive visible-light-driven photo-catalyst for environmental applications.