Titanium dioxide (TiO₂) nanotubes have attracted much attention due to their formation, properties, and functionality in recent years. Many methods have been used to obtain the nanotubes, such as template synthesis, hydrothermal, sol–gel, and electrochemical anodization. Compared to others, the electrochemical anodization method makes it possible to grow dense and well-aligned nanotube layers on pure and/or alloyed titanium surfaces. However, for enhanced photocatalytic activities, the parameters of the anodization process such as applied potential, time, and electrolyte composition should be tightly controlled to obtain regular, well-aligned, and continuous nanotube arrays. Alternatively, by the formation of heterojunctions such as α-Fe₂O₃/TiO₂, the performances of the photocatalysts can be boosted due to the shifts of absorption range into the visible region and narrower band gaps of the hierarchical structures. In this study, TiO₂ nanotubes were obtained by electrochemical anodization on Ti foil in ethylene glycol, ammonium fluoride and distilled water-based electrolyte under constant voltage and varying anodization durations. Herein, it was aimed to observe the effects of the anodization time on the length and diameter of the nanotubes, which have significant roles on the photocatalytic activity. Besides the investigation of the anodization parameters, the heterogeneous structure, α-Fe₂O₃/TiO₂, was formed on anodized surfaces to scrutinize the improvement of the photocatalytic properties. The TiO₂ nanotubes were characterized through XRD and SEM to determine the phase structure and morphology, respectively. The variation of optical bandgap values of α-Fe₂O₃/TiO₂ samples depending on the processing parameters was determined by using a UV–Vis spectrophotometer. The photocatalytic performances of the α-Fe₂O₃/TiO₂ photocatalysts were revealed using an aqueous solution of methylene blue. Photocatalytic degradation rates and kinetic study of α-Fe₂O₃/TiO₂ photocatalysts were evaluated by a comparative approach. The highest degradation efficiency was achieved as 85% using the α-Fe₂O₃ coated photocatalyst with the anodization time of 30 min and anodization voltage of 30 V.

近年来，二氧化钛（TiO ₂）纳米管由于其形成，性质和功能而备受关注。已经使用了许多方法来获得纳米管，例如模板合成，水热，溶胶-凝胶和电化学阳极氧化。与其他方法相比，电化学阳极氧化方法可以在纯钛和/或合金化钛表面上生长致密且排列良好的纳米管层。但是，为了增强光催化活性，应严格控制阳极氧化工艺的参数（例如施加的电势，时间和电解质组成），以获得规则的，排列良好的连续碳纳米管阵列。可替代地，通过异质结如α-Fe的形成₂ ö ₃ /二氧化钛₂因此，由于吸收范围向可见光区域的转移以及分级结构的较窄带隙，光催化剂的性能得以提高。在这项研究中，在乙二醇，氟化铵和蒸馏水基电解质中，在恒定电压和不同阳极氧化持续时间下，通过在钛箔上进行电化学阳极氧化，获得了TiO ₂纳米管。在此，旨在观察阳极氧化时间对纳米管的长度和直径的影响，其对光催化活性具有重要作用。除了阳极氧化参数的调查，异质结构，的α-Fe ₂ ö ₃ /二氧化钛₂在阳极氧化的表面上形成了α，以检查光催化性能的改善。通过XRD和SEM对TiO ₂纳米管进行了表征，以确定其相结构和形貌。的α-Fe的光学带隙值的变化₂ ö ₃ /二氧化钛_2种，这取决于处理参数的样品是通过使用紫外可见分光光度计测定。α-Fe的光催化性能₂ ö ₃ /二氧化钛₂的光催化剂，使用亚甲基蓝的水溶液显现出来。光催化降解速率和动力学研究的α-Fe ₂ ö ₃ /二氧化钛₂通过比较方法评估光催化剂。最高降解效率用的是达到85％的α-Fe ₂ ö ₃涂覆的光催化剂用的30分钟30 V的阳极氧化时间和阳极化电压