For the first time, one-dimensional phase-modulated structures consisting of two different layered Aurivillius phases with alternating five and six perovskite-like layers were obtained by atomic layer deposition (ALD) on the surface of TiO₂ nanotubes (Nt). It was shown that the use of vertically oriented TiO₂ Nt as the substrate and the ALD technology of a two-layer Bi₂O₃-FeO_x sandwich-structure make it possible to obtain a layered structure due to self-organization during annealing. A detailed study by scanning electron microscopy (SEM) and transmission electron microscopy (TEM) showed that the coating is conformal. Raman spectroscopic analysis indicated the structure of the layered Aurivillius phases. Transient photocurrent responses under Ultraviolet–Visible (UV-Vis) light irradiation show that the ALD coating benefits the efficiency of photon excitation of electrons. The results of the photoelectrocatalytic experiments (PEC) with methyl orange degradation as a model demonstrate the significant potential of the synthesized structure as a photocatalyst. Photoluminescent measurement showed a decrease in the probability of recombination of photogenerated electron–hole pairs for ALD-coated TiO₂ Nt, which demonstrates the high potential of these structures for use in photocatalytic and photoelectrochemical applications.

Iron oxides are widely used as catalysts for photo-Fenton-like processes for dye oxidation. In this study, we report on the synthesis of an α/γ-Fe₂O₃ mixed-phase catalyst with magnetic properties for efficient separation. The catalyst was synthesized using glycine–nitrate precursors. The synthesized α/γ-Fe₂O₃ samples were characterized using scanning electron microscopy, X-ray diffraction spectroscopy (XRD), Raman shift spectroscopy, X-ray photoelectron spectroscopy (XPS), and vibrating sample magnetometer (VSM). The diffraction peaks were indexed with two phases, α-Fe₂O₃ as the main phase (79.6 wt.%) and γ-Fe₂O₃ as the secondary phase (20.4 wt.%), determined using the Rietveld refinement method. The presence of Fe²⁺ was attributed to oxygen vacancies. The mixed-phase α/γ-Fe₂O₃ catalyst exhibited remarkable photo-Fenton-like degradation performance for Rhodamine B (RhB) in neutral pH. The effects of operating parameters, including H₂O₂ concentration, catalyst concentration, and RhB concentration, on the degradation efficiency were investigated. The removal rates of color were 99.2% after 12 min at optimal conditions of photo-Fenton-like oxidation of RhB. The sample exhibited a high saturation magnetization of 28.6 emu/g. Additionally, the α/γ-Fe₂O₃ mixed-phase catalyst showed long-term stability during recycle experiments, with only a 5% decrease in activity.

Currently, the issue of minimizing the environmental impact of anthropogenic activities and improving the quality of water resources is topical. The paper